Blaye is located on the right bank of the Gironde estuary (which is some 3 km (1.9 mi) wide at this point), close to the A10 autoroute, 56 km (35 mi) north of Bordeaux. There is a rail line with occasional freight trains, but no passenger services. A small ferry crosses the Gironde to Lamarque, in Medoc.
In ancient times Blaye (Blavia) was a port of the Santones. Tradition states that the Frankish hero Roland was buried in its basilica, which was on the site of the citadel. It was early an important stronghold which played an important part in the wars against the English (who burnt it in 1352) and the French Wars of Religion (when it was the site of a Spanish naval victory in 1593). The duchess of Berry was imprisoned in its fortress in 1832–1833. The town was formerly named Blaye-et-Sainte-Luce and was renamed Blaye in June 1961. The town has a citadel built by Vauban on a rock beside the river, which contains the ruins of a medieval castle, Château des Rudel(fr), and the ruins of Basilica of Saint-Romain, which holds the tomb of Charibert II, king of Aquitaine, and son of Clotaire II. Nearby, Fort Paté, on an island in the river, and Fort Médoc on its left bank, also of the 17th century, completed Vauban's defenses of the water approaches of Bordeaux . The citadel of Blaye, its city walls, Fort Paté and Fort Médoc (the latter in nearby Cussac-Fort-Médoc) were listed in 2008 as UNESCO World Heritage Sites, as part of the "Fortifications of Vauban" group.