Charles, Prince of Viana was the eldest son of John I of Aragon, he as born in 1421 and died in 1461. He was married to Agnes of Cleves who died a few years after their marriage, he was then proposed as a candidate for Isabella of Scotland, and then for a daughter of Edward I of Portugal. He quarrelled a lot with his father but was recognised as his heir eventually. Had he outlived his father, would he have become King of Aragon and Navarre as was thought to be the case, or would his step mother pitch for Ferdinand the Catholic to be King? Also, who might Charles marry? Isabella, a daughter of Edward, or Isabella I?