Work began around 1200 on the construction of a Cathedral on the site of an old parish church from the 12th century. The present "Münster Unserer Lieben Frau" (Cathedral of our Beloved Lady) was modeled after the Minster in Basel.

The choir, the Late Romanesque transom, the nave and the flanking towers were completed before the death of the last Zähringer duke, Bertold V (1218).

In 1220, the plans were revised and construction continued in the Modern Gothic style, which at that time had reached its zenith in France.

The west tower - the "most beautiful tower of Christianity"- was finished in 1330.

During the long construction time, the remainder of the old parish church was used for mass, and then gradually torn down as sections of the Cathedral reached completeion.

It is likely that the new building of the Late Gothic chancel was designed by the cathedral master workman Johannes von Gmünd. The cornerstone was laid in 1354. The chancel was not fully finished until 1513, due to political and economic problems in the city and poor management.

The Cathedral achieved its present form at the beginning of the 16th century. However, it has been almost constantly under construction or renovation. Because of high levels of air pollution, the ongoing efforts to maintain the Cathedral are a race against time.