Vlad Tepes, aka Vlad Dracula and his brother Radu were imprisoned with their father Vald Dracul by the Ottoman Sultan, within a year Vlad Dracul was released but he supported the Hungarian King (a Catholic) during the Varna Crusades, Vlad Dracula and Radu were kept as prisoners to secure that Vlad Dracul didn't go too far in his Christian support. Eventually the boys were released Radu stayed and coverted to Islam, and Vlad Dracula went back to Wallachia and stayed an Orthodox Christian who had both Orthodox Christian and Roman Catholic allies.