King Juan II of Aragon was a monarch who ruled from 1458 to 1479. He was born in 1398 and was the son of King Ferdinand I of Aragon and Queen Eleanor of Alburquerque. His reign was marked by political challenges, including conflicts with the Catalan nobility and issues related to the Crown of Aragon. Juan II is known for his efforts to strengthen royal authority and centralize power. He played a significant role in the War of the Two Peters, which was a conflict between Aragon and Castile. His reign laid the groundwork for the eventual unification of Spain under his son, Ferdinand II of Aragon.