Strängnäs (strĕngˈnĕsˌ) [key], city (1990 pop. 11,420), Södermanland co., E Sweden, on Strängnäsfjärden, an arm of Lake Mälaren. Manufactures include medical supplies and pharmaceuticals. Known in the 11th cent. as a pagan site for human sacrifices, it became (c.1120) the seat of a Christian bishop. The city has a famous cathedral (begun in the mid-13th cent.), where several Swedish kings are buried. Gustavus Vasa was elected (1523) king of Sweden there.