The original cathedral was built between 1019 and 1500 in Romanesque and Gothic styles. The late Romanesque building, destroyed by the 1356 Basel earthquake, was rebuilt by Johannes Gmünd, who was at the same time employed for building the Freiburg Münster. Ulrich von Ensingen, architect of the towers at the Ulm Minster and the Strasbourg Cathedral, extended the building from 1421. Hans von Nußdorf completed the southern tower in 1500.