Eleanor of Aragon, Queen of Castile in the context of Eleanor of Sicily

The House of Barcelona was a medieval dynasty that ruled the County of Barcelona continuously from 878 and the Crown of Aragon from 1137 (as kings from 1162) until 1410. They descend from the Bellonids, the descendants of Wilfred the Hairy. They inherited most of the Catalan counties by the thirteenth century and established a territorial Principality of Catalonia, uniting it with the Kingdom of Aragon through marriage and conquering numerous other lands and kingdoms until the death of the last legitimate male of the main branch, Martin the Humanist, in 1410. Cadet branches of the house continued to rule Urgell (since 992) and Gandia. Cadet branches of the dynasty had also ruled Ausona intermittently from 878 until 1111, Provence from 1112 to 1245, and Sicily from 1282 to 1409. By the Compromise of Caspe of 1412 the Crown of Aragon passed to a branch of the House of Trastámara, descended from the infanta Eleanor of the house of Barcelona.

Henry III of Castile (4 October 1379 – 25 December 1406), called the Suffering due to his ill health (Spanish: Enrique el Doliente, Galician: Henrique o Doente), was the son of John I and Eleanor of Aragon. He succeeded his father as King of Castile in 1390.