Linköping, city and capital of Östergötland län (county), southeastern Sweden, on the Stång River near its outflow into Rox Lake. The site has been settled since the Bronze Age. During the Middle Ages it attained commercial importance and was surpassed as a cultural and religious centre only by Uppsala and Lund. Several important diets were held there during the reign of Gustav I Vasa. In 1598 at Linköping the battle against King Sigismund III Vasa preserved the Evangelical Lutheran Church in Sweden and secured the Swedish throne for the Vasa dynasty. Two years later four of Sigismund’s partisans were beheaded on Stora Torget (Main Square), an event known as “the Linköping Massacre.” After a fire in 1700 the city declined.
Industrial development came with the building of the Göta and Kinda canals and the Stockholm–Malmö railway. The city is a rail junction, with aircraft, freight car, and automobile industries. Linköping University, affiliated with the University of Stockholm, was founded in 1970. In 1975 it became an independent university. Pop. (2005 est.) mun., 137,636.