The Abbey of Cluny establish in 1067 the Church and the Priory Saint-Martin. For nearly three centuries, the monastic community of Aix Island, extended its spiritual influence on La Rochelle and its region by governing a large number of parishes.
But because of the intensification of the conflicts between France and England, the priory, repeatedly plundered and damaged, was abandoned in 1343. Of the whole church, only the eastern wing of the priory remains today, and the transept, the northern apse and the crypt of the church. The crypt, which certainly dates back to the foundation of the church, testifies of the religious history of the island.