War of the Castilian Succession
The death of King Henry IV of Castile in 1474 set off a struggle for power called the War of the Castilian Succession (1475–1479). Contenders for the throne of Castile were Henry's one-time heir Joanna la Beltraneja, supported by Portugal and France, and Henry's half-sister Queen Isabella I of Castile, supported by the Kingdom of Aragon and by the Castilian nobility.