The monarchy began a modest recovery from the low it had reached during the reign of his father, Henry I, and he added the Vexin region and the viscountcy of Bourges to his royal domaine.

In 1077, he summoned a great host to relieve Dol-de-Bretagne and prevent the annexation of Brittany by William the Conqueror, who was forced to capitulate and make his peace with Philip.

[13] In 1107, Pope Paschal II met Philip and the future Louis VI in Saint-Denis, cementing a century-long alliance between the kingdom of France and the papacy against the Holy Roman Empire.

[14] Although the king was mainly concerned with internal politics, troops from his own demesne joined the ranks of William of Normandy during the Conquest of England in 1066,[15] of Odo of Burgundy during the Franco-Spanish campaign against the Almoravids in 1087,[16] and of the various leaders of the First Crusade,[17] in which his brother Hugh of Vermandois was a major participant.

[18] Although the marriage produced the necessary heir, Philip fell in love with Bertrade de Montfort, the wife of Fulk IV, Count of Anjou.

In 1101, the sentence was renewed by Urban II in Poitiers, despite the protest of William IX, Duke of Aquitaine, who entered the church with his knights to prevent his suzerain from being excommunicated on his lands.

For after he had abducted the Countess of Anjou, he could achieve nothing worthy of the royal dignity; consumed by desire for the lady he had seized, he gave himself up entirely to the satisfaction of his passion.

They carried the body in a great procession to the noble monastery of St-Benoît-sur-Loire, where King Philip wished to be buried; there are those who say they heard from his own mouth that he deliberately chose not to be buried among his royal ancestors in the church of St. Denis because he had not treated that church as well as they had, and because among those of so many noble kings, his own tomb would not have counted for much.Philip's children with Bertha were: Philip's children with Bertrade were: