He was a son of Maurice V of Craon and Mathilde Berthout. In 1313, Amaury III became Seneschal of Gascony, holding the position until 1316. He received a charter in 1315 to build a bastide at Créon, with permission of King Edward II of England. He was appointed as the Seneschal of Gascony from 1320 until 1322. With the creation of Lieutenants-General to protect the borders of the border provinces, King Charles IV of France in 1323, then Philip IV in March 1331, buy successively the hereditary positions of Seneschal of Touraine, Anjou and the Maine from Amaury III.
Amaury died on 26 January 1333, and was buried in the Convent of the Cordeliers, Angers.
Craon married firstly Isabelle, daughter of Guillaume IV le Valet, lord of Ste-Maure, they had the following known issue:
He married secondly Béatrice, daughter of John IV, Count de Roucy and Jeanne de Dreux, they had the following known issue: