She was the daughter of King Philip I of France and Bertrade de Montfort.

[1] Cecile's first marriage was arranged while Prince Bohemond I of Antioch was visiting the French court seeking support against the Byzantine emperor, Alexios I Komnenos.

She sailed for Antioch at the end of 1106 and became lady of Tarsus and Mamistra in Cilician Armenia.

Cecile married Prince Tancred of Galilee, regent of Antioch, in late 1106.

[2] In 1133, Pons was besieged at his castle of Montferrand by Imad ad-Din Zengi, atabeg of Mosul, and Cecile appealed to her half-brother King Fulk of Jerusalem to come to his aid.