Bayonne (bäyônˈ) [key], town (1990 pop. 41,846), Pyrénées-Atlantiques dept., SW France, in Gascony, on the Adour River near its entrance into the Bay of Biscay. Despite a shifting sandbar at the mouth of the Adour, it is a seaport, exporting sulfur, oil, and natural gas. The town also has metallurgical, chemical, aeronautical, tuna fishing, leather, and wood industries. French and Spanish, as well as Basque, are spoken there. At Bayonne, Napoleon I forced Charles IV and Ferdinand VII of Spain to abdicate (1808). At the end of the Peninsular War, Bayonne successfully resisted a British siege. Bayonne gives its name to the bayonet, invented there in the 17th cent. The Cathedral of Bayonne (13th cent.) is copied from those of Soissons and Reims. There is a Basque museum and a fine arts museum, left to the city by the painter Bonnat, who was born there. Parts of the town's Roman and medieval walls are preserved, as are Vauban's fortifications (17th cent.).