OLERON, an island lying off the west coast of France, opposite the mouths of the Charente and Seudre, and included in the department of the Charente-Inférieure, has an area of 59 square miles. It is about 18 miles in length from north-west to south-east, and 7 in extreme breadth; the width of the strait separating it from the mainland is at one point less than a mile. The greater part of the island is very fertile, but there are also some extensive salt marshes, from which a considerable quantity of salt is made. The chief products are corn, wine, fruit, and vegetables. The population of the island, which is mostly Protestant and supplies excellent sailors, numbered 18,244 in 1881; that of the chief town, Château d’Oleron, on the south-east coast, was 1727. Other towns are Saint-Georges d’Oleron (4943) and Saint-Pierre d’Oleron (1535). Oleron, the Uliarus Insula of Pliny, gave its name to a mediaeval code of maritime laws, for the origin and history of which see Sea Laws.