page_title: Crown of Castile
section_title: Ascension of the Trastámara dynasty
hierarchical_section_title: Crown of Castile / History / Crown of Castile from the rule of Ferdinand III until the ascension of Charles I / Ascension of the Trastámara dynasty
caption_attribution_description: English: This map shows the Crown of Castile and its geographical evolution during centuries.
context_page_description: The Crown of Castile was a medieval polity in the Iberian Peninsula that formed in 1230 as a result of the third and definitive union of the crowns and, some decades later, the parliaments of the kingdoms of Castile and León upon the accession of the then Castilian king, Ferdinand III, to the vacant Leonese throne. It continued to exist as a separate entity after the personal union in 1469 of the crowns of Castile and Aragon with the marriage of the Catholic Monarchs up to the promulgation of the Nueva Planta decrees by Philip V in 1715.
  The Indies, Islands and Mainland of the Ocean Sea were also a part of the Crown of Castile when transformed from lordships to kingdoms of the heirs of Castile in 1506, with the Treaty of Villafáfila, and upon the death of Ferdinand the Catholic.
  The title of "King of Castile" remained in use by the Habsburg rulers during the 16th and 17th centuries. Charles I was King of Aragon, Majorca, Valencia, and Sicily, and Count of Barcelona, Roussillon and Cerdagne, as well as King of Castile and León, 1516–1556.
context_section_description: On the death of Alfonso XI a dynastic conflict started between his sons, the Infantes Peter (Pedro) and Henry, Count of Trastámara, which became entangled in the Hundred Years' War (between England and France). Alfonso XI had married Maria of Portugal with whom he had his heir, the Infante Peter. However, the King also had many illegitimate children with Eleanor of Guzman, among them the above-mentioned Henry, who disputed Peter's right to the throne once the latter became king.
  In the resulting struggle, in which both brothers claimed to be king, Pedro allied himself with Edward, Prince of Wales, "the Black Prince". In 1367, the Black Prince defeated Henry II's allies at the Battle of Nájera, restoring Pedro's control of the kingdom. The Black Prince, seeing that the king would not reimburse his expenses, left Castile. Henry, who had fled to France, took advantage of the opportunity and recommenced the fight. Henry finally was victorious in 1369 in the Battle of Montiel, in which he had Peter killed.
  In 1371 the brother of the Black Prince, John of Gaunt, 1st Duke of Lancaster, married Constance, Peter's daughter. In 1386, he claimed the Crown of Castile in the name of his wife, the legitimate heir according to the Cortes de Seville of 1361. He arrived in A Coruña with an army and took the city. He then moved on to occupy Santiago de Compostela, Pontevedra and Vigo. He asked John I, Henry II's son, to give up the throne in favor of Constance.
  John declined but proposed that his son, the Infante Henry, marry John of Gaunt's daughter Catherine. The proposal was accepted, and the title Prince of Asturias was created for Henry and Catherine. This ended the dynastic conflict, strengthened the House of Trastámara's position and created peace between England and Castile.
caption: Expansion of Castilian territory.