He was the last of the weak late medieval kings of Castile. During Henry's reign the nobles increased in power and the nation became less centralised. He was born in 1425 and was the son of John II of Castile and Maria of Aragon, daughter of King Ferdinand I of Aragon. In 1440, at the age of fifteen, he was married to Blanche II of Navarre. The marriage was never consummated. In 1453, after thirteen years. He married second time. They have got one daughter. As his nickname was "impotent", this child wasn't from him. Henry IV died 11 December 1474.