Elder daughter of Richard Neville, 16th Earl of Warwick.
The Earl had probably harboured expectations, on behalf of his two daughters, of marriage to very wealthy English noblemen, but was blocked by the matchmaking of Edward IV on behalf of the Queen’s sisters.
The response was to draw Edward’s brother, George, Duke of Clarence, away from the Yorkist faction to marry Isabel and make a bid for the throne himself. Isabel died after giving birth to her fourth child.
Her husband George accused one of Isabel’s ladies in waiting of poisoning her and, acting as though he were king, had her tried in a local court under his control which, not surprisingly, found her guilty and she was executed. The conviction was posthumously overturned by Edward IV.