Castilian Civil War of 1437–1445

The Castilian Civil War of 1437–1445 was a civil war in which two noble factions fought for power in the Crown of Castile. On one side was Constable Álvaro de Luna, King John II of Castile, and Henry Prince of Asturias. On the other side was the noble League led by Infantes of Aragon John and Henry, sons of Ferdinand of Antequera, who was the regent of Castile during the minority of John II. Although the Infantes of Aragon faction won in 1441, imposing their conditions in the Medina del Campo ruling, the final victory went to the royalist faction and the Constable, who won the decisive battle of Olmedo. According to historian Carme Batlle, Álvaro de Luna is primarily responsible for the war. Following his victory over the Infantes of Aragon during the truces of Majano, Luna's "authoritarian excesses" escalated and led to a civil war. Although Batlle places the war's start in 1439.