John I of Aragon was a king who ruled from 1387 to 1396. He was the son of Peter IV of Aragon and Eleanor of Portugal. His reign was marked by political challenges, including conflicts with the Crown of Castile and internal strife within his kingdom. During his rule, John I focused on strengthening the monarchy and maintaining stability in Aragon. He also sought to improve relations with neighboring regions, although his efforts were often complicated by the ongoing power struggles of the time. His reign ended with his death in 1396, after which he was succeeded by his son, Martin I of Aragon.