He was an active soldier, an ally in the field of Philip Augustus, the French king and his cousin,[1] making him an opponent in campaigns in France and elsewhere of Richard I of England.

He presided over that of his cousin Conrad of Montferrat at the Siege of Acre, marrying him to Isabella I of Jerusalem, daughter of Amalric I, whose marriage he annulled.

[9] He was captured by Angevin forces under the mercenary leader Mercadier and Prince John in a Normandy campaign, in 1197.

[9] Pope Celestine III was unsympathetic to Philip, confined at Rouen and then, after an escape attempt, at Chinon.

[17] In his last year as bishop he founded the Pentemont Abbey, a Cistercian convent whose later buildings in Paris remain to the present day.