The area was known before 1140 as "Bremgarten", though the city wasn't founded until almost a century later. In 1230, a settlement was founded near the present location of Bremgarten. Then, in 1238/39 it was mentioned as "Bremegarten". In 1258, it was granted city right by Rudolf I of Habsburg. Bremgarten's population grew rapidly, and it became an important market town with an outstanding Latin school. Because it was part of the Habsburg lands, the residents of Bremgarten fought at the Battles of Morgarten (1315) and Sempach on the Habsburg side.