Only seven when his father died, Thomas became Count of Perche under the regency of his mother and her new husband Enguerrand III, Lord of Coucy.
In the end, Louis VIII renounced the English crown, but in the interim fought the forces of William Marshal, 1st Earl of Pembroke.
In the decisive Battle of Lincoln of 1217, Thomas, the commander of the French forces, was killed.
Following Thomas's death in 1217, King Philip II of France gained control of the castles of Moulins-la-Marche, Bonsmoulin, and Bellême, which had been contested since 1182.
[3] Thomas’s uncle William, who was also Bishop of Châlons, succeeded him as the Count of Perche.