Île d'Oléron

Oléron lies off the coast of Saintonge, guarding the approaches to the Charente estuary. Its medieval castle belonged to the dukes of Aquitaine, and the island passed between French and English control during their long struggle. After La Rochelle surrendered, Richelieu ordered new fortifications on Oléron in 1630. The citadel later formed an advanced defence for the naval arsenal established at Rochefort under Louis XIV.