His family was a benefactor of both the Vaux-de-Cernay and Port Royal monasteries, and close to the court of Philip II of France.

[5][6] During his tenure as abbot he oversaw the repair and expanded the abbey, including the maintenance of existing buildings, and grew the number of monks.

[7] Following the Cistercian model of adhering to the Rule of Saint Benedict, he dressed in a simple if not threadbare fashion.

[7] As he was an effective administrator, William of Auvergne, the Bishop of Paris asked Theobald to manage the affairs of the Abbey of Port-Royal-des-Champs.

[7] His reputation grew and king Louis IX asked Theobald to pray for the fertility of him and his wife Margaret.

[7] Placed on his tomb was a simple slab decorated with a crozier and a short Latin inscription: "Hic jacet Theobaldus abbas" (Here lies Abbot Thibauld).

[7] During the French Revolution, the abbey was destroyed and Theobald's relics were burned, with the exception of his skull which is preserved in the Sainte-Marie Chapel of the Church of Saint-Brice of Cernay-la-Ville [fr].