city, Guipúzcoa provincia (province), in the comunidad autónoma (autonomous community) of Basque Country, northern Spain, lying east of Bilbao on the Bilbao–San Sebastián railway. The city was chartered by Alfonso XI of Castile in 1346. Its chief industry since the 16th century has been the manufacture of armaments, particularly finely engraved small arms. Other metallurgical products are sewing machines, auto parts, and surgical instruments. Its armament works made it a target of heavy Nationalist aerial bombardment during the Spanish Civil War of 1936–39. Papermaking has grown in importance. Pop. (2007 est.) mun., 27,404.