Strängnäs is a locality and the seat of Strängnäs Municipality, Södermanland County, Sweden with 15,363 inhabitants in 2020. It is located by Lake Mälaren and is the episcopal see of the Diocese of Strängnäs, one of the thirteen dioceses of the Church of Sweden. Prominently located on a hilltop, Strängnäs Cathedral, built between 1291 and 1340, is an important landmark. Etymology. The city's name is first encountered in 1120, in reference to the Diocese.
https://en.wikipedia.org/wiki/Str%C3%A4ngn%C3%A4s