My rough translation:
Former church of the Augustinian hermits monastery. Built in 1268. Baroquization dates to 1740. Frescoes on the arches are from the Council time [Council of Constance, 1414-1418]. Rich murals by Constance painters Storer 1635, Stauder 1733, Spiegler 1738 and Marie Ellenrieder 1844.
The church is in the old town (Altstadt) section of Constance.