Aunis (ōnēsˈ) [key], small region and former province, W France, on the Atlantic coast. It is now part of the Charente-Maritime and Deux-Sèvres depts. and includes the islands of Ré and Oléron. La Rochelle, the historic capital and one of the leading ports of the region, and Rochefort are the chief cities. A part of Aquitaine, it was recovered from England in 1373 and incorporated into the French crown lands.