Philip I of Castile, also known as Philip the Handsome, was a Spanish nobleman born in 1478. He was the son of Maximilian I, Holy Roman Emperor and Mary of Burgundy. Philip became the Duke of Brabant and was married to Joanna of Castile, the daughter of Ferdinand II of Aragon and Isabella I of Castile. In 1506, Philip briefly became the King of Castile after his wife's mother, Isabella, passed away. His reign was short-lived, as he died in 1506, leaving Joanna to rule. Philip's legacy is intertwined with the unification of Spain and the Habsburg dynasty.