Philip I (born July 22, 1478, Bruges—died Sept. 25, 1506, Burgos, Spain) was the king of Castile for less than a month before his death and the founder of the Habsburg dynasty in Spain.
Philip was the son of the future Holy Roman emperor Maximilian I of Habsburg and Mary of Burgundy. At his mother’s death (1482) he succeeded to her Netherlands dominions, with Maximilian acting as regent for him during his minority. When Philip became of age, his interest in the Netherlands was soon subordinated to his hopes for the Spanish succession. In 1496 Philip was married to Joan the Mad, daughter of Ferdinand II the Catholic of Aragon and Isabella I the Catholic of Castile; Joan later inherited the crown of Castile. From January 1502 to March 1503 Philip and Joan lived in Spain and received homage as prospective heirs to the kingdoms of Aragon and Castile. Isabella died in 1504, leaving the crown of Castile to Joan. Philip was recognized as king consort. Because Joan was in the Netherlands at the time, Ferdinand, in accordance with Isabella’s will, acted as regent.
Philip soon began to oppose his father-in-law, who was unwilling to give up his control of Castile, and in early 1506 sailed to Spain to claim his wife’s inheritance. On his voyage his ships had to take shelter in England, where King Henry VII forced him to agree to two treaties, the first of which secured English support for Philip’s Castilian rights. The second (April 30, 1506), the Intercursus Malus, was a trade agreement disadvantageous to the Netherlands. In Castile, Philip, backed by the nobility, soon raised a strong army. He negotiated Ferdinand’s withdrawal on June 27, 1506. By that time Joan’s mental condition had deteriorated further, and Philip assumed sole control. He was in the process of organizing his administration when he was stricken with a fever and died. His son Charles I of Spain (the Holy Roman emperor Charles V) became king of Aragon and Castile on Ferdinand’s death in 1516, thus firmly establishing the dynasty that was to govern Spain for nearly two centuries.