an island in the Indian Ocean, in the Mascarene Islands: an overseas region and department of France, having been in French possession since 1642. A number of far-flung and uninhabited islands, some located on the opposite side of Madagascar, were also politically part ofRé union until 2007, when they were transferred to the French Southern and Antarctic Lands. Capital: Saint-Denis. Pop: 767 000 (2004 est). Area: 2510 sq km (970 sq miles)