Yeah it was in chester. Edward died a few days after putting it down so probably from battle wounds but that's my own conjecture.

His dad most likely killed his aunt as he invited her to a feast and she died at like 35 right before it. Also if I remember correctly that made mercia go into rebellion as he also deposed her daughter a few months after so the reason he didn't conquer jorvik is because he pissed off the mercians. If he wouldn't have done that then yeah he probably could have. You say technicality I say failed from poor decisions.

Æthelstan still conquered jorvik. I get that his dad and aunt did more but you really can't call jorvik a technicality.