Ferdinand II of Aragon

Ferdinand was born during a period of turbulence, with King John II and his son, Charles, Prince of Viana (Ferdinand's elder half-brother) embroiled in open conflict.[11] Ferdinand was by no means meant to inherit the Crown of Aragon. That privilege was reserved for Charles but John II was not having it. Within the Crown of Aragon, John had the support of Aragon, Sardinia, Sicily, Majorca and the Remences of Catalonia while Charles had the support of Catalonia and Navarre. Valencia chose to remain neutral while Louis XI of France and Henry IV of Castile allied with John and Charles respectively.[12] After Charles' unexpected death on 23 September 1461, Ferdinand was made John's undisputed heir.[13]

In February 1462, war broke out in Catalonia with the commencement of the First War of the Remences led by Francesc de Verntallat.[14] The peasants revolted against the Consell del Principat with the hope of receiving royal support. On 11 March, Queen Joanna sensing danger, departed Barcelona for Girona, with the 10-year old Prince Ferdinand in tow. They hoped to receive protection from the French garrison stationed in Girona. In May, the deputy leader of the Consell, Francesc Pallarès, along with two other former leaders, were executed by the Generalitat for colluding with the Queen. This meant civil war, once more.[15]

An army of the Consell was formed and placed under the command of Hug Roger III, Count of Pallars Sobira. After besieging and capturing Hostalric on 23 May, Roger marched on Girona, where he was received warmly on 6 June while the Queen and the Prince took refuge in the citadel, Força Vella, all throughout June. Gaston IV, Count of Foix, leading a French army, took Girona on 23 July and rescued the Queen and Prince.

By this time, King John II and King Louis XI had signed the Treaty of Sauveterre (3 May) and the Treaty of Bayonne (9 May) in which Louis pledged 4,200 French Knights to John's cause in return for 200,000 escut as payment. And until the payment was made, Louis received Roussillon and Cerdagne as collateral, along with the right to garrison Perpignan and Cotlliure.[16] With this, the Consell named John II "an enemy of Catalonia" and offered the Principality to three different foreigners; Henry IV of Castile, Peter of Coimbra and René of Anjou.[12][17]

When the General Cortés was convened, at Zaragoza on 6 February, 1468, Queen Joanna, afflicted with late-stage breast cancer, was too sick to preside over. So, the now sixteen year old Ferdinand did so instead. He handled the sessions as if he was a well-seasoned veteran politician in his 60s. The Queen could not have been more proud of her son, but just two weeks later her serene highness died, which to say devastated Ferdinand would be an understatement. Diego de Valera insists that a wonderful odor arose from her corpse, implying she was a Saint. King John II was then battling the French in the north, and it was Ferdinand who saw to his mother’s funeral arrangements. Then, in Valencia, where the regional Cortés was indifferent to the ongoing war, Ferdinand addressed the city’s nobility with tears streaming down his face. He first paid his due reverence to his deceased mother and said: "Lords, you are well aware of the hardships my lady mother underwent to keep Catalonia within the House of Aragon. I see my lord father old and myself very young. Therefore I place myself in your warm and capable hands and ask you to please embrace and guide me as if I were your own son."[7][18][6]

The speech received an ecstatic response with some Nobles swearing oaths of fealty then and there. With this, Valencia; the most prosperous kingdom within the Crown of Aragon at the time, joined the war on the side of the royalists and the war waged on until John II and Prince Ferdinand entered Barcelona in 1471 and the Consell signed the Capitulation of Pedralbes. Here, Ferdinand displayed his magnanimity by convincing his father to issue a general pardon to all their former opponents (except Hugh Roger III).[19][20]

In between 1463 and 1469, Ferdinand had managed to bag multiple victories against all manner of foes (the French led by the Duke of Lorraine, the Castilians led by John of Beaumont, the Portuguese led by the Constable of Portugal and the Catalans led by the Count of Pallars Sobira).[21] Some of his notable victories were at Vildamat, Berga, Alt Emporda, Els Prats del Rei, Bellegarde, Collioure, and Salses. He also led the liberation of Navarre from the French, when he, along with his father, entered Perpignan on 1 February 1473 amidst jubilation.[13]

By the time he was just 17, he was a proven battlefield commander and a shrewd diplomat (earning praise from Louis XI of France himself).[19][20] In 1473, he was made a Knight of the Golden Fleece by Charles the Bold, Duke of Burgundy. He was the last recipient of that honor from a member of the founding house: the House of Valois-Burgundy, before the death of Charles at the Battle of Nancy in 1477 ended its male-line permanently.[22]

As heir apparent to the Crown of Aragon, Ferdinand was the subject of many royal matches. A notable one being a marriage proposal made by Charles the Bold, Duke of Burgundy for his daughter, Mary of Burgundy. He eventually married Isabella, the half-sister and heir presumptive of Henry IV of Castile, on 19 October 1469 in Valladolid, Kingdom of Castile and Leon.[30] Since the marriage was done against Henry's wishes, Isabella's status as his heir presumptive was revoked and she was disinherited in favour of Henry's daughter; Princess Joanna. Although Isabella never gave up her claim to the title; Princess of Asturias, from 1469 to 1475, they had to rely on Ferdinand's regal title; King of Sicily.[31]

Before the marriage, Ferdinand was asked to sign the humiliating Capitulations of Cervera on 5 March 1469. Most people, like Alfonso de Palencia, Pedro de Peralta, Archbishop Margarit and even Castilians like Archbishop Carrillo, Gutierre de Cardenas and Juan Pacheco, wondered why a royal prince would even contemplate signing such a document. But Ferdinand, being the shrewd politician he is, was playing the long game.[32][20]

On 12 December 1474, Henry died in Madrid. When news reached Segovia, where Isabella was residing, she immediately convened the Courts of Castile the following day, disinherited her niece Joanna and proclaimed herself Queen of Castile with Ferdinand as her "legitimate husband". Ferdinand was not present for all this because, at the time, he was campaigning against the French occupying Roussillon. When he got word, he was incandescent with fury. He immediately rode for Segovia, where he was given a royal entry on 2 January 1475.[33]

Immediately, a new agreement of understanding was drafted with Archbishop Carillo representing the interests of Ferdinand and Cardinal Mendoza representing the interests of Isabella. The Concord of Segovia, completed on 5 January, was not an agreement between husband and wife but one between two rival political parties.[34] In it, Ferdinand renounced all claims to the throne of Castile as closest male heir of the House of Trastamara. Isabella was recognized as sole owner of the Kingdom with it passing to her descendants at the time of her death. All official documents, the coin, the seal and the proclamations will be headed by the names of both with Ferdinand taking precedence over Isabella. Both their arms were merged into one with Isabella's Eagle of Saint John and Ferdinand's motto "Tanto Monta" ("it amounts to the same [cutting as untying]") added in. It was decided that the arms of the House of Trastamara; the arms of Castile y Leon, would take precedence over the arms of Aragon y Sicily in their new joint heraldry. Ferdinand was recognized jure uxoris King of Castile as Ferdinand V of Castile, with near equal powers to those of Isabella.[34][35] Identical equal powers (with the added benefit of being made the supreme authority on the joint Crown's foreign, military and social policies) were ceded by Isabella to Ferdinand on 28 April 1475, at the outbreak of the Castilian War of Succession.[36][37] This document, nullifying the separation of monarchical powers established in the Concord of Segovia, signified the commencement of a reign of true equals.[38][39][40][20]

Ferdinand the Catholic swearing the fueros as the Lord of Biscay at Guernica in 1476.

Ferdinand the Catholic, flanked by Cardinal Mendoza and the Duke of Alba, at the Battle of Toro (1476).

Shortly after Ferdinand and Isabella were invested as the Monarchs of Castile, Queen Joanna's husband; King Afonso V of Portugal, declared Isabella a usurper and took up his wife's cause. According to him, she was the legitimate heir of Henry IV, and as her husband, he, the legitimate jure uxoris King of Castile (as Alfonso XII). Isabella had no option but to reciprocate by claiming the throne of Portugal (as the daughter of Isabella of Portugal) and declaring war on Afonso.[41]

On one side was the Crown of Aragon and the pro-Isabella faction of Castile. On the other, the Kingdom of Portugal and the pro-Joanna faction of Castile. The 3 most powerful Houses of Northern Castile (the House of Enriquez, the House of Mendoza and the House of Alvarez de Toledo) formed the pro-Isabella faction because of their familial ties to Ferdinand. The lesser Hidalgos (who made up 2/3 of Castile's nobility) led by the House of Pacheco-Giron, the House of Zuniga and the Archbishop of Toledo (the supreme ecclesiastical authority of Castile) formed the pro-Joanna faction.[42] France supported Afonso and Joanna (because of a wider war raging in Roussillon, Cerdagne and the Italian Peninsula with Aragon) and Burgundy supported Ferdinand and Isabella (for the same reason France supports Portugal). The Kingdom of Navarre was going through a civil war, so it, along with the Taifa of Granada and the Kingdom of Galicia, chose to remain neutral.[43]

Ferdinand, as Captain-General, led the Castilian-Aragonese army while Afonso and the "Perfect Prince" led the Castilian-Portuguese army. Under the leadership of Ferdinand, the pro-Isabella Castilians won some decisive battles in Trujillo, Burgos, Cantalapiedra, Castronuño, Sieteiglesias, Cubillas, Villalonso, Portillo, Villaba and Zamora.[44][45] On 1 March 1476, Ferdinand (along with Cardinal Mendoza and the Duke of Alba) secured a major victory at the Battle of Toro, which essentially crushed all hopes of a Portuguese victory on land. After signing a Treaty with Afonso V on 23 September 1475, Louis XI of France sent a wave of French armies under Alain I of Albret, all throughout March–June of 1476, to push into Castile via Hondarribia.[46] Ferdinand not only crushed this French Invasion but also managed to gain a foothold in the Kingdom of Navarre by conquering Viana and Puente La Reina. He then acted as arbitrator between the warring factions of Navarre while gaining the right to station 1,000 men-at-arms in Pamplona. This victory shielded Aragon and Castile from any future French offensives.[46] Although Ferdinand was winning on land, at sea, the Portuguese, along with Norman pirates led by Guillaume Coullon, were gaining the upper hand (especially after the Battle of Guinea and the Battle of Elmina).[47][48] On 9 October 1478, Ferdinand pressured Louis XI to sign the Treaties of Saint-Jean-de-Luz and Guadalupe, in which France recognized Ferdinand and Isabella as the legal Monarchs of Castile in return for Ferdinand breaking all ties with Maximilian I, Duke of Burgundy.[49]

Emboldened by the victory at Elmina, Afonso V decided to undertake a last-ditch invasion of Castile. In February 1479, a Castillan-Portuguese army commanded by Garcia de Meneses, Bishop of Evora, penetrated into Extremadura. The objective was to occupy and reinforce the strongholds of Mérida and Medellin, controlled by Beatriz Pacheco, Countess of Medellin and supporter of Joanna. Ferdinand immediately dispatched Alonso de Cardenas, Master of the Order of Santiago, with a Castilian-Aragonese army, to face this threat. On 24 February, near the hill of Albuera, the two forces jostled for dominance. Despite Cardenas having been outnumbered 2:1, he completely routed the invasion force and Ferdinand quickly put Merida and Medellin under siege.[50] In June 1479, Ferdinand launched an offensive against the rebel Archbishop of Toledo, who was forced to surrender. This signified the end of hostilities towards Ferdinand and Isabella within Castile. The pro-Joanna faction disintegrated, with its leaders; the Marquis of Villena, the Maquis of Cadiz and the Count of Ureña, submitting themselves to the Queen's mercy.[51] All that remained was Portugal itself and with Pope Sixtus VI revoking his papal dispensation for the marriage between Afonso and his niece, Joanna, the legitimacy of Afonso V as King of Castile fell by its foundations.

The document that put an end to the war, the Treaty of Alcáçovas-Toldeo, was drafted on 4 September, 1479. It was ratified by Afonso V of Portugal in Alcáçovas on 8 September, 1479 and by Ferdinand and Isabella in Toledo on 6 March, 1480. In it, Afonso renounced all claims to the throne of Castile and Isabella did the same to the throne of Portugal. The treaty wasn't harsh on any party apart from Queen Joanna herself, who was required to renounce all regal claims associated with Henry IV and retire to a nunnery for the rest of her life.

On 20 February 1479, Ferdinand's father, King John II of Aragon, died and that same year Ferdinand succeeded him as King. Now, he was King of Castile, Leon, Aragon, Sicily and Count of Barcelona. And on 14 April, 1481, in the Cortes of Calatayud, he granted his wife Isabella, the same powers that he had received on 28 April, 1475, designating her as co-regent, governor and administrator of the kingdoms of the Crown of Aragon.[52] This signified the symbolic union of the Crown of Castile and the Crown of Aragon into one: the Crown of Spain. In the words of a letter drafted by the Town Council of Barcelona to the Town Council of Seville: "Now...we are brothers."[53]

Isabella dictating her last will while Ferdinand sits beside her

On 12 October 1504, Ferdinand's wife and queen proprietor of Castile; Isabella I, had her last will drafted and notarized, in which she stipulated their daughter Joanna as "the true queen, natural lady and universal successor". On 23 November that same year, she signed a codicil in which she stipulated that if Joanna was not physically present in the Kingdom or "being in them, she does not want to or cannot attend the governorship" it was to pass over to Ferdinand and no other, who in turn was to set up a regency headed by him for their grandson; Prince Charles, until he reached the legal age of 20. With this, Isabella set up a contingency plan in case Joanna's diagnosis was accurate and also sidelined her son-in-law; Archduke Philip, who was already bitter about Isabella outright rejecting his request of being afforded the same title as her husband: de jure uxoris King of Castile. The will made it crystal clear that Philip was simply Prince-consort of Castile with no position in the line of succession or any hand in Castile's government.[58] This was all on paper, while the real situation was anything but this clear-cut. 3 days after signing the codicil, Isabella died and since Joanna was in Flanders, thus started the 1st regency of Ferdinand.

Regardless of what the will stipulated, Ferdinand's position in Castile was precarious. Despite having become King of Castile even before he became King of Aragon, and having channeled a good portion of his prime (35 years in total) for matters pertaining to Castile (the skirmishes with Henry IV, the War of the Castilian Succession, the pacification of Galicia, the Granada War, Columbus' expeditions etc...), he was still legally a foreigner. And after Isabella's death, his legal role in Castile was limited to temporarily presiding over the government until Joanna's arrival. Since Ferdinand was the one who spearheaded the centrist policies that saw a good chunk of the castilian nobility deprived of their feudal lands, rights and privileges,[59][7][60] from their perspective this was the ideal time for payback. And it was in their best interest to swiftly replace this seasoned monarch with a novice while they had the law on their side. Coincidentally, these were all the same nobles that joined the anti-Isabelline faction during the War of the Castilian Succession. They, led by Diego Lopez de Pacheco, Marquess of Villena, Pedro Fernandez de Cordoba y Pacheco, Marquess of Priego, Juan Alonso Pérez de Guzmán, Duke of Medina Sidonia and Juan Téllez-Girón, Count of Ureña demanded Ferdinand immediately vacate Castile. This was when the Marquess of Villena uttered the most infamous words: "¡Viejo Catalanote, vuélvete a tu tierra!" (Old Catalan, go back to your country!).[61][62]

Ferdinand only had a handful of nobles, albeit powerful, on his side. They included: Fadrique Álvarez de Toledo, Duke of Alba, Íñigo López de Mendoza, Count of Tendilla, Fadrique Enríquez, Admiral of Castile, Bernardino Fernández de Velasco, Constable of Castile and Diego Fernández de Córdoba y Mendoza, Count of Cabra.[63] With their backing, he sought to empower the regency clause stipulated in Isabella's will by having Joanna declared "incapable of governing the realm" in front of the Castilian Cortés convened at Toro. This didn't go as planned but a curious opportunity presented itself that proved greatly beneficial to Ferdinand's political aspirations: it seems Joanna's mental state had worsened while in Flanders, thus preventing Philip from immediately sailing over to Castile and establishing himself via his wife because up until then, Joanna's mental health issues were merely rumor. But if the castilian nobles were to witness first hand her true state, everything could go wrong for Philip.[64] On top of all this, Philip was forced to attend to the plight of Guelders, which was then occupied by Charles of Egmont. But all through this, Philip always had one staunch ally; his father, the Emperor Maximilian. But for whatever reason, Philip opted to also ally himself with Maximilian's enemy; Louis XII of France (possibly to incentivize him into threatening Ferdinand in the pyrenees front) early that year by signing the 1st Treaty of Blois on 24 September 1504 , in which Philip recognized Louis' claims to the Duchy of Milan. The treaty also included a marriage between Philip's son; Charles, and Louis' daughter; Claude.[65] This infuriated Maximilian and also forced Ferdinand to make an alliance of his own.

On 12 October 1505, Ferdinand and Louis signed the 2nd Treaty of Blois, which was an alliance strengthened by marriage. This treaty basically overwrote the aforementioned 1st treaty with Philip, and it stipulated that Ferdinand would marry Louis' niece; Germaine of Foix and restore the ceased assets and titles of the Angevin party of Naples, and in return, Louis would transfer his disputed claims to Southern Italy and the throne of Jerusalem to her while also ensuring any military action taken by the Archduke and/or the Emperor against either Ferdinand or Louis would have to overcome a joint French-Aragonese force.

This devastated Philip, who in just one day, had lost both his allies (Maximilian and Louis) and possibly the Crown of Aragon (because any male children born to Ferdinand and Germaine would bypass Joanna). This wasn't all beneficial to Ferdinand either. His second marriage, to a French princess no less, cost him the approval of Castile's majority population, who unlike the nobility, had lauded Ferdinand as their King. The people saw it as a blatant betrayal of Isabella. Ferdinand basically handed his political opponents material to further discredit him. But in the end, it was Philip who was mauled. So he entered into fresh negotiations with Ferdinand.[66]

On 24 November 1505, a concord was signed between Ferdinand and Philip (represented by Filiberto de Veyre) at Salamanca. In it, Ferdinand recognized Joanna's and by extension, Philip's, right to rule in Castile. While the couple would be invested as de jure uxoris King and Queen proprietor of Castile, Ferdinand would run the realm's everyday affairs as "Governor". The royal income would be split in half between the couple and Ferdinand. Isabella's half of the Indies would pass over to the couple while Ferdinand retained his half as per the solemn papal bull, while royal appointments were to be agreed upon by both parties.[67][68] This treaty didn't last long and finally, on 8 January 1506, Philip and Joanna set sail from Flanders towards Castile.

Ferdinand receiving the traditional kissing of the hand by the Juntas Generales after having been sworn in as Lord of Biscay under the Guernica

The nobles that sided with Ferdinand tried to convince him to confront Philip on the battlefield. As did those that sided with Philip (especially the Duke of Medina Sidonia). The couple initially planned to land in Seville to meet up with the Duke of Medina Sidonia and march into Northern Castile at the head of an army. But Juan Manuel, Lord of Belmonte (who would soon go onto be the de facto Prime Minister of Castile under Philip) discouraged Philip from taking any such rash action.[67] After a brief shipwreck in England, where Philip was forced to make concessions to Henry VII in return for his freedom, he initially planned to land in Biscay, which strongly rebuffed him saying "the land is loyal to the one sanctioned under the tree; the Lord of Biscay",[7][69] so he opted for Corunna instead. He landed there at the head of an army of German mercenaries on 26 April 1506. The castilian nobility was quick to flock to him. A curious event was Francisco Jiménez de Cisneros, Archbishop of Toledo, switching sides from Ferdinand to Philip. Nobody knew at the time this was orchestrated by Ferdinand himself.

Ferdinand faces Philip's entourage alone and unarmed

Both parties agreed to settle their disputes in a peaceful manner with the Archbishop serving as mediator. On 20 June, 1506 both men met for the first time (since 1504) at Remesal where Ferdinand promised to give up all "claims and aspirations" to the Castilian throne. And on the 27 and 28, the Treaty of Villafáfila was ratified in Benavente and Villafáfila respectively. In it, Ferdinand politically ceded to Philip, who was recognized as "King and Governor of Castile" and also "Lord of the Indies" although the rents and legal ownership of the Indies were split equally between Ferdinand and Philip. Most importantly, they agreed to keep Joanna away from running the Kingdom and if any tried to change this, both men would prevent it. With this, Philip's position in Castile was solid and Ferdinand departed Castile for the Crown of Aragon.[70] Philip was invested by the Cortés of Valladolid as Philip I of Castile, and the nobles that sided with Ferdinand were forced to take oaths of fealty. But the Grand Tendilla vehemently refused, claiming that Mendozas couldn't and wouldn't serve "a pretender".[67][71][72]

After Ferdinand departed Castile, and Philip established himself there by making huge concessions to the nobility that supported him, it seemed as if the makeup of the Iberian peninsula had turned into what it was prior to 1475. Castile and Aragon were again, two separate realms, ruled by two separate monarchs who were hostile towards each other. Although Philip's reign was short (just shy of 3 months), a lot happened in that short timeframe that threatened to eradicate everything Ferdinand and Isabella had worked for for 29 years.

The conflict started with Ferdinand publicly renouncing every concession he had made in the Treaty of Villafáfila as soon as he was back in Aragon. He said he was "coerced" into making them and contrary to what the treaty says, his daughter Joanna is the one and only Monarch of Castile and he will staunchly defend his daughter's god-given rights if any were to impede on them. This was the signal for the nobles who had sided with Ferdinand early on to start rebelling from inside Philip's government. The Admiral of Castile (a cousin of Ferdinand) and the Constable of Castile pressured Philip to let Joanna accompany him at every public event and co-sign every one of his decrees since she was the legal "reina propietaria". Turns out, Philip's grasp on Castile wasn't as secure as he thought. But he wasn't going to take this lying down.[67][73]

Philip started with refusing to extradite Cesare Borgia, who was imprisoned at the time in the Castle of La Mota, to Aragon despite him being an Aragonese POW. He then barred merchants from the Crown of Aragon from dealing with the Casa de Contratación in Seville or from sponsoring direct expeditionary fleets into the Indies. This was basically a trade blockade. Ferdinand replied in kind by sponsoring privateer raids from Biscay targeting Flemish merchant vessels. He also expelled Castilians from the Kingdom of Naples. A notable one being the Grand Captain (although Ferdinand and him remained life-long friends and Ferdinand bestowed on him with the most number of ducal titles held by any one man in all of Spain). Philip was being pressured on all sides but things were not over yet.[72][67]

A grain shortage hit Castile in 1506, coincidentally corresponding with the time Philip was invested as King. A deficiency in harvest was there since 1501 but this was the culmination of poor harvests and hoarding. In 1486, as part of his overall agrarian reforms, Ferdinand imposed a ceiling price of 124 maravedis per fanega on wheat.[74] This was revoked by Philip in 1506 as part of the aforementioned concessions made to the nobility. Little did he know the nobles had started to buy what little wheat was left and hoard it to artificially inflate the prices. This spiraled into a famine and the entire country was restless. But Philip wouldn't be alive to see that.[74]

On 16 September 1506, Philip had fallen dangerously ill after drinking a glass of cold water following a game of ball. It is recorded he did get better and went about his affairs comparatively well until he suddenly fell dead on 25 September while residing at the Casa del Cordón in Burgos. A rumor spread that the owner of the aforementioned residence; the Constable of Castile (who also happened to be Ferdinand's son-in-law), had poisoned the King at the behest of Ferdinand. An autopsy was carried out that put these rumors to rest.[75] Immediately following Philip's death, Joanna became beyond delirious, even prohibiting Philip's remains from being interred. After his last rites, a regency council was created presided over by the Archbishop of Toledo. He in turn sent word to Ferdinand to return and take over the regency as was stipulated in Isabella's will. Ferdinand refused until the request was co-signed by the Cortés of Castile, which it was. Thus started the 2nd regency of Ferdinand.

When the Cortés of Castile sent word for Ferdinand to take over the regency, he was in Naples undertaking much needed reform in the new Kingdom of the Two Sicilies and its accompanying island-states (like Malta). As such, he endorsed Joanna to rule the best she could until he came over. The situation in Castile was not looking good. Apart from the aforementioned famine, the nobles having been emboldened by Philip's concessions, had set out to carve out semi-autonomous states of their own at the expense of the central government. Ferdinand sent over one of his most trusted military commanders; Pedro Navarro, Count of Oliveto to assess the situation and take necessary countermeasures. By 1507, after having limited the nobles to Seville, Navarro was to kickstart the long anticipated "La Empresa de África" campaign with the end goal being the Spanish standard flying over the Holy Land.

In 1508, Ferdinand set his eyes on the newly established Kingdom of Bardis, which had gained its independence from the Kingdom of Fez on January that year with the help of the Venetians. Bardis was a corsair state that was accused of raiding the coastline of Granada and this was the casus belli Ferdinand intended to use. On 23 July 1508, a fleet led by Count Navarro conquered Peñón de Vélez de la Gomera. The Wattasid Sultan beseeched the neighboring Muslim kings to intervene on his behalf but none did. But there was one that was furious at this blatant attempt at conquest; Ferdinand's son-in-law Manuel, King of Portugal, because this was rightfully the Portuguese area of influence as was established in the Treaty of Tordesillas. Ironically, the Wattasid Sultan managed to bring the Spaniards and the Portuguese together when he tried to bite more than he could chew by besieging Asilah in 1508, which was at the time, part of the Portuguese Maritime Empire. Navarro was quick to send reinforcements from Vélez de la Gomera to break the siege.

This unofficial alliance was made official by both Ferdinand and Manuel in 1509 by signing the Treaty of Sintra. The treaty established that, on the one hand, Portugal desist from any idea of conquest of the rock of Vélez de la Gomera and the rest of the territories that extended to the east, which would correspond to Spain because it was in the jurisdiction of the Kingdom of Fez, thus leaving Melilla (already in Spanish hands since 1497) and Cazaza protected against any Portuguese claims. On the other hand, Spain recognized Portuguese sovereignty over the North African territories between Vélez and Cape Bojador (on the Atlantic coast). Additionally, it was agreed that whoever violates the terms of the treaty should pay a fine of 100,000 gold doubloons. This treaty was never violated or amended even with the 1529 Treaty of Zaragoza. This was basically the greenlight for the Spanish conquest of North Africa.

An Aragonese armada under the command of Admiral Ramón de Cardona (rumored to have been a bastard son of Ferdinand), carrying a joint Castilian-Aragonese army under the command of Diego Fernández de Córdoba y Arellano, Marquis of Comares, all under the spiritual guidance of Cardinal Cisneros had already conquered Mers El Kébir, which was then a part of the Kingdom of Tlemcen, on 13 September 1505. This was to serve as a launchpad into the Kingdom of Tlemcen. All was ready for the Spanish conquest of Oran (1509).

On 16 May 1509, a large fleet carrying a total of 16,000 fighting men, that cost Ferdinand a whopping 40 million maravedis, set sail from Cartagena to Mers El Kébir. From there, the Spanish under the command of Pedro Navarro, launched an amphibious assault on the city of Oran which was quickly followed by an all-out ground assault on the 18th. The city fell within a day and on the 20th, Cardinal Cisneros entered the city amidst jubilation. This was followed by a string of victories at Béjaïa, Algiers, Tunis, Tlemcen, and Tripoli. By 1510, Ferdinand was master of a network of presidios along a 2,500-mile stretch of Maghribi coastline, from Cape Bojador on the Atlantic to Tripoli on the Mediterranean. The Italian humanist; Peter Matyr wrote:

"From now on, nothing will be difficult for the Spaniards; they will undertake nothing in vain. They have sown panic throughout Africa."[76]

On 8 September, 1510, Emery d’Amboise, Grandmaster of the Order of the Knights Hospitaller, based at Rhodes, wrote to Ferdinand congratulating him on his recent victories in the African cities of Bougie and Tripoli. The Knights of Saint John had ordered solemn processions to mark the conquest of Tripoli, he related, and he expressed confidence that the Spanish would soon reach Mamluk Egypt, where Amboise’s military order would join forces with them to “liberate” the Holy Land. He wrote:

"May it please God that all Christians, following Your Majesty’s example, take up arms against the infidels who have afflicted the Christian nation for so long. And in their lands may we raise the banner of the cross and recover the Holy Land. May God Almighty carry out Your Majesty’s wishes and allow you to proceed with and complete the conquest of Africa as far as Egypt, where we hope to join forces with Your Highness’s army and serve God in this worthy endeavor."[77]

Much like the Grandmaster, some Spaniards (most notably Cardinal Cisneros) did hold evangelizing aspirations in Africa and worked toward that end.[78] And Ferdinand was happy to represent his African conquest as a crusade, as a war undertaken for the faith and one that led inevitably toward a Christian recovery of the Holy Land. This, of course, allowed him to make use of the funds that were raised through the cruzada levy. For at least fifteen years, this continued to be the light in which Ferdinand’s African enterprise was cast. In March 1510 Pope Julius II issued the solemn papal bull "Sacrosanctae Romane", in which he praised Ferdinand’s efforts “to bring an end, through blood and fire, to the perfidious sect of Islam.” Julius went on to express optimism that the African expedition that Ferdinand was planning for that summer would lead, eventually, to the ultimate “destruction of all vestiges of the impious superstition [Islam]".[79]

Pope Julius’s words do not indicate whether he envisioned the conversion of African Muslims and the salvation of their souls or merely their death or subjugation as the geographical boundaries of Christendom were extended. For all the lip service Ferdinand paid to the ideals of crusade and (possibly) evangelization, in practice on the ground the King proved flexible and pragmatic, ever willing to work out an ad hoc system to preserve his conquered territories, even if that entailed abdicating the evangelical responsibilities imposed by a papal bull. Two months following Julius’s Sacrosanctae Romane, Ferdinand wrote to Pedro Navarro, giving the commander instructions on how to negotiate terms with Muley Abdallah, the emir of recently conquered Bougie. What Ferdinand proposed was a condominium of sorts: he suggested that he would populate the African cities along the coast with Christians, but that the defeated emir would be allowed to control as much of the interior as he desired, maintaining control over his subjects, as well as all “rents, goods, and jurisdiction” (rentas, bienes, jurisdicción), while the coast should belong to Ferdinand and his successors. Along the coast, Ferdinand would enjoy complete jurisdiction over both the Christian and Muslim populations.[80][81] Ferdinand would now be "Imperator totius Africa". In recognition of his vassalage, the Muslim ruler would pay an annual tribute to Ferdinand. The arrangement allowed for the possibility of Ferdinand’s acquiring new Muslim subjects. While Spanish men of the cloth may have held evangelizing aspirations in Africa, such a mission does not appear to have been a priority for Ferdinand. If one were to look for Iberian analogues to this arrangement, it might be useful to think of Muley Abdallah as a ta’ifa king entering into a relationship of vassalage with Ferdinand.

Seven months later, in December of the same year, Ferdinand wrote to Navarro again, this time giving him instructions to execute an attack on Tunis the following summer (1511). Ferdinand expressed hope that Navarro’s expedition might conquer a large swath of land stretching into the interior. In the event that that should occur, wrote the king, he would "receive the Muslims of the interior as mudéjar subjects".[82] This represented a significant departure from the injunctions to evangelize that were present in Sacrosanctae Romane and the earlier "Ineffabilis et summi". It seems that, by late 1510, Ferdinand had opted for a more traditionally medieval Iberian custom of allowing ongoing Islamic practice, by a mudéjar population now subject to a Christian ruler. As Tlemcen was incorporated into the Crown of Aragon, Ferdinand’s policy vis-à-vis Muslim subjects was really no different from his policy within the Crown of Aragon proper. That region of eastern Iberia would have a Muslim population up until his grandson; Charles I, applied the edict mandating conversion or exile in 1526.[83][84] Even as it accorded with his policy in Aragon, Ferdinand’s approach in Africa stands in sharp contrast to the policies being simultaneously implemented in Granada.

In 1511, Pedro Navarro was restationed to Italy with the Holy League declaring war on France. With that came the end of "La Empresa de África". The campaign was a massive success and although this process of Mediterranean expansion is less well known today than the contemporaneous incursions into the Americas, in the early sixteenth century it occupied a position of utmost importance in royal policy and, not unlike its American counterpart, Spain’s Mediterranean expansion required legal buttressing in order to fend off European competitors and this would later serve as the blueprint for the Scramble for Africa.

Ferdinand's most notable accomplishments would be sponsoring Columbus, which led to the discovery of the Americas and the completion of the Spanish Reconquista. The idea of restoring Don Rodrigo's kingdom was a goal instilled on him by his childhood tutor Margarit i Pau. Ferdinand could be classified as an immensely pragmatic, liberal soul (from freeing the Catalan Remences of their "6 evil customs" and granting them emphyteusis[85] to actively shielding the Mudejars of Valencia from reprisals during the Granada War[86] to legalizing interracial marriages throughout the Spanish realms[87]). He was devout as a personal follower of Christ but he never let religion dictate his secular policies. He had no problem exploiting religious institutions for the betterment of his realm. For this, he's seen as less devout than his zealous wife.[88][89]

Under his reign, there were upwards of 6 higher educational institutions built throughout Spain. But the University of Valencia, established in 1502, is arguably the greatest indicator of Ferdinand's vision as to what a proper education constitutes. A contemporary description of the students of the University of Valencia:

Even the youngest scholars are accustomed never to keep silence; they are always asserting vigorously whatever comes uppermost to their minds, lest they should seem to be giving up the dispute. Nor does one disputation, or even two a day prove sufficient, as for instance at dinner. They wrangle at breakfast; they wrangle after breakfast; they wrangle before supper and they wrangle after supper. At home they dispute, out of doors they dispute. They wrangle over their food, in the bath, in the sweating room, in the church, in the town, in the country, in public, in private. At all times they are wrangling.[90]

In the words of Machiavelli; he rose from being a disputed king of a divided crown to the foremost monarch of christendom (second to not even the Holy Roman Emperor). And along with him rose Spain; from being a patchwork of kingdoms sitting at the edge of the continent to the top powerplayer of continental europe and by extension, the World.[91]

One of Ferdinand's most infamous traits was his reluctance to keep his word. He earned many critics due to this but he was always open about this particular trait of his. His reasoning was that he, nor anyone, should be obligated to stay within self-imposed, fixed parameters in the face of a total dissolution of them. He famously said:

Only God's infallibility is resolute. Everything else is subject to change. Anyone who claims otherwise is either a browbeater or a simpleton; neither of which I want to be.[92]

Ferdinand the Catholic's royal arms in the Spanish Embassy to the Holy See.

Ferdinand recognized the importance of progress (or the lack thereof in Christian Iberia) and he appropriated innovative inventions from the hub of progress; the Italian Peninsula, and gave them his own little twist. An example would be the concept of residential ambassadors and permanent embassies. The Italian city-states possessed them in a micro scale, limited to communicating within the peninsula. Inbetween 1480 and 1490, Ferdinand launched this in a macro scale, with resident spanish ambassadors in all the prominent courts: Rome, Venice, London, Brussels, Cairo and the migratory Imperial court. The spanish ambassador to England would also serve as the unofficial spanish ambassador to Scotland. The spanish foreign service under Ferdinand was so efficient that foreign monarchs were inclined to use spanish diplomats (like Dr. Puebla and Bishop Ayala) as their own representatives to other nations.[93]

Ferdinand the Catholic on his throne, flanked by two shields with the emblem of the Royal Seal of Aragon. Frontispiece of a 1495 edition of Catalan constitutions.[94]

Ferdinand was a master of Pactism. He, quite accurately, could be called the Father of Pactism in Spain. In the fashion of the Roman Emperor Augustus, he ruled his many realms with an iron-grip but he never made the inhabitants feel like they were dealing with an autocrat. In Catalonia for instance, he was initially rebuffed as his father's viceroy to the principality just before the outbreak of the catalan civil war. After winning the war, Ferdinand didn't insist upon holding his victory over the principality's head as most would. He immediately embarked upon trying to find the root of the conflict, which was three fold: 1) The Catalans were still bitter about the Compromise of Capse. 2) The Catalans were under the impression that the House of Trastamara didn't give much regard to their ancient fueros. 3) The Catalans blamed the Trastamaras for them losing their 12th-14th century splendor and prestige. Ferdinand couldn't change his lineage but he could change the perception of it. He undertook a number of drastic reforms that culminated with Barcelona regaining its lost position as the prime spot of the western mediterranean. He enlisted the help of the Mamluk Sultan Quitbay by having him sign off on an exclusive Cairo-Barcelona trade route in 1484 that proved extremely lucrative. Now that prosperity was restored, Ferdinand set about enforcing the rule of law by first drafting the Constitució de l'Observança, which called for compliance, even by the King, to the laws of the land. Ferdinand famously said: "It would be of little value to make laws and constitutions if they were not observed." Then he established the Real Audiencia de Cataluña as the highest civil court of the land in 1492. With these, any notion of absolutism had dissipated and the Principality fully backed Ferdinand in all his endeavors. It is not like these reforms did not have its critics. Ferdinand was almost killed on the steps of the Plaça del Rei on 18, October 1492.

Ferdinand's legacy, in a nutshell, would be the physical manifestation of the idea that was "Spain". By 1513, the territory that encompasses modern-day Spain had been completely acquired and it was larger than at any point in history; stretching from the Pacific coast of Central America to Tripoli in the Mediterranean. If custodianship is a valid metric, one could argue Ferdinand's Spain had a realistic foothold in the Levant; with Mamluk Sultan Al-Ghuri bestowing custodianship of all christians living in Jerusalem, Bethlehem, Ramallah and Beirut to Ferdinand in 1504.[95] In his own words:

For more than 700 years the Crown of Spain has not been so great nor so resplendent as it is now, both in the West and in the East, and all, after God, because of my work and labor.[96]

Probably Ferdinand's greatest blunder was the double marriage he jumped into with the Austrian Habsburgs on 20 January 1495, where his heir apparent; Infante John, was set to marry Emperor Maximilian's daughter; Princess Margaret and Maximilian's heir apparent; Archduke Philip, was to marry his daughter; Infanta Joanna (who was third-in-line to the throne at the time). In the short-term, this proved greatly beneficial to both monarchs in the sense that it shook France; their immediate enemy, to its core. And any sense of danger dissipated when in 1497 Infante John and Princess Margaret announced they were expecting a child, which tightly secured the Trastamara line. Nobody could've anticipated what happened next.

On 4 October 1497, while on his way to his daughter's wedding in Portugal, a messenger conveyed to Ferdinand that his son lay dangerously ill in Salamanca. He immediately rode to John with haste and reached his bedside moments before he died. That same day, John, Prince of Asturias and Girona died in the arms of his father. On 8 December that same year, Princess Margaret gave birth to a stillborn daughter which effectively ended the joint-Trastamara line. Almost an year later, the next heir-apparent; Isabella of Aragon, Queen-consort of Portugal, died on 23 August 1498 in Zaragoza while giving birth to a son; Infante Miguel da Paz. Hope was rekindled in the sense that under him, the entirety of Iberia (Castile, Aragon and Portugal) could be united. This proved fleeting because on 19 July 1500, he too died in Granada, effectively paving the way for Joanna and her husband Philip, to ascend to the throne of Spain.

Ferdinand was adamant on keeping the Habsburgs away from the throne. And Joanna's rumored mental health issues weren't helping. He tried to convince Isabella to bypass Joanna in the Castilian line of succession in favor of their 4th child; Mary of Aragon, Queen-consort of Portugal and her husband; Manuel, King of Portugal, and promised that he would do the same for the Aragonese line of succession (women weren't allowed to ascend to the Aragonese throne without amending the existing articles of succession beforehand). But Isabella was equally adamant about sticking to tradition and the existing articles of primogeniture. The only other option Ferdinand had left was to split the Crown of Aragon from the union, disinherit Joanna (and by extension, Philip) and name a competing heir. This was something he found himself incapable of doing to his wife (at least, while she was alive).

So, in 1502, Joanna and Philip were sworn in as the Princes of Asturias and Girona before the Cortés of Castile and Aragon respectively. From this point forth, the couple's grip on Castile was solid while in Aragon, right after their swearing-in ceremony, Alonso of Aragon, Archbishop of Zaragoza and Valencia, loudly proclaimed that this was purely ceremonial since the articles of succession are yet to be amended and Ferdinand was still capable of sirering male offsprings down the line. Regardless, now that Joanna was heir-apparent to the throne of Spain, her rumored mental health issues rose from being mere court gossip to the center of Europe's political stage.

These rumors did have teeth as is seen in Isabella's own last will and testament. On 26 November 1504, Isabella died, but not before recognizing Joanna as her Universal Heir & Reina Propietaria (Queen Proprietor) in Castile as Joanna I of Castile and by extension, Philip as King-consort. But in this same will, she included a phrase where if Joanna "proved incapable of ruling" or she outright didn't want to rule, Ferdinand was to assume the regency until their grandson Charles reached the age of 20. Ferdinand tried to empower the regency clause but apart from the noble houses of Alvarez Toledo led by the Duke of Alba, Mendoza led by the Grand Tendilla, Enríquez led by the Admiral of Castile, Frias led by the Constable of Castile, none of the other Hidalgos (who made up 2/3 of Castile's nobility) supported Ferdinand.[97] In fact they, led by the Marquess of Priego (the Grand Captain's nephew) and the Marquess of Villena, were vehemently opposed to Ferdinand staying in Castilian soil much less preside over a regency.

Philip briefly contemplated the option of armed conflict against Ferdinand by landing in Andalusia and sweeping up from the south. But he was talked out of it by the Lord of Belmonte, saying that depriving Ferdinand of any options and pushing him into a corner would leave him only one viable path, a path that leads straight through Philip himself.[7] So, the couple opted to land in Corunna on 28 April, 1506 accompanied by an army of German mercenaries and the anti-Ferdinand faction was quick to flock to Philip. Ferdinand had one of two options: 1) start a civil war and risk a possible French-Austrian offensive or 2) retire peacefully. He chose option 2 and after meeting Philip and his "entourage" at Remesal, he signed the Treaty of Villafáfila on 27 June 1506 and retired to Aragon where he went about restructuring and reforming the newly conquered Kingdom of Naples. On 12 July 1506, the Cortés of Valladolid legitimized Philip as the new de jure King of Castile as Philip I of Castile. But he reigned for less than 3 months before succumbing to typhoid fever while in Burgos on 25 September 1506. By this point, Joanna was beyond delirious and a regency council was created, presided over by the Archbishop of Toledo. But now the Hidalgos, emboldened by Philip, seized portions of the country and challenged the central government's authority. On top of this, a famine hit as a result of devastated crop yields. The Cortés of Castile begged Ferdinand to take over the regency but he didn't come back until 1509, wherein which he led an army against the Marquess' of Priego and Villena and was given a triumph in Valladolid. That same year, in the face of his daughter's growing mental health issues, he confined her to the Palace of Tordesillas. To ease her transition, he allowed her daughter, Infanta Catherine, to accompany her during her confinement. Ferdinand is recorded to have said: "Sending my daughter into Tordesillas proved more draining than facing French cannons on the battlefield."[98]

From 1506-1516, Ferdinand, on top of ruling the Crown of Aragon and the Indies, also ruled as Regent of the Crown of Castile. Still adamant about keeping the Habsburgs out of his own realms if possible, he fathered a son; John, Prince of Girona, who was born to his second wife; Queen Germaine of Foix, on 3 May 1509. The child didn't survive for more than a few hours and it was back to square one. Ferdinand then briefly contemplated making his namesake, spanish-born grandson; Infante Ferdinand, with whom he even shared a birthday, his heir in direct opposition to Charles but was talked out of it by the Archbishop of Toledo. On 23 January 1516, he died in Madrigalejo, and his last will and testament was unveiled; in which he had named Charles and Joanna, as his heir-apparents. Joanna's appointment as co-monarch was strictly nominal (as she would not be released from her confinement till the day she died) while the 16-year old Charles was who the actual burden of governance fell on. Ferdinand even dictated Charles be considered of legal age despite him being a minor with the express purpose of him taking over immediately because by this point, Spain couldn't afford an empty throne. This Charles didn't do (at the behest of his primary councilor; William de Croÿ), which cost Spain dearly because while Spain lay idle, its enemies (namely, Selim the Lion) didn't.