Philip I (Philip the Handsome), 1478–1506, Spanish king of Castile (1506), archduke of Austria, titular duke of Burgundy, son of Holy Roman Emperor Maximilian I and Mary of Burgundy. Heir to his mother's Burgundian dominions (which included the Low Countries), he was held prisoner after her death (1482) by the city of Ghent, which objected to Maximilian's claim to be regent for Philip. Maximilian secured his son's release in 1485, but not until 1493 did he establish control over the Low Countries in Philip's name. In 1496, Philip married Joanna, daughter of Ferdinand II (of Aragón) and Isabella I. When Joanna became (1504) queen of Castile under her father's regency, Philip contested Ferdinand's rights and in 1506 became joint ruler of Castile with his wife. His death in the same year acutely aggravated Joanna's insanity. Ferdinand again became joint ruler of Castile with Joanna, while Philip's dominions in the Low Countries passed to his son (later Holy Roman Emperor Charles V).

Philip I, 1052–1108, king of France (1060–1108), son and successor of Henry I. He enlarged, by arms and by diplomacy, his small royal domain. In order to prevent the union of England and Normandy under a single ruler, he consistently supported Robert II of Normandy (Robert Curthose). In spite of his efforts, royal power remained weak. Philip's practice of simony and his consequent opposition to the reforms of Pope Gregory VII brought him into conflict with the Holy See. Among the issues were simony and control of marriage policy, an issue fueled by Philip's private life. Philip repudiated his first wife, Bertha, daughter of the count of Holland, and married, over the opposition of the Roman Catholic Church, Bertrada of Montfort, wife of Count Fulk of Anjou, while both Bertha and Fulk were still living. Philip, excommunicated by popes Urban II and Paschal II, remained defiant until 1104. In his last years his son, Louis VI, ruled for him.