sentences:  The area was extensively developed in the early part of the 13th century, when the abbeys of Maillezais, Nieul-sur-l'Autise, Saint-Michel-en-Herm, and the Absie St. Maixent joined together for the project.The monks dug canals to manage the water and create more arable land.In 1317, after the final suppression of the Albigensians in France, Pope John XXII restructured the allocation of French bishoprics, creating two new episcopal sees, each with a cathedral, out of the diocese of Poitiers.