The church was established together with Augustinian cloister in 1350 by Charles IV and it takes a unique position in history of Prague gothic architecture. Due to its layout of octagonal central building, consecrated to the patron of Emperor Charles IV, Charlemagne, it should have had the look of his octagonal burial church in Aachen. There is also a unique vault with diameter of 24 m, which comes from 1575. Later on the church was consecrated to the Virgin Mary. The cloister ambulatory, which is located in the west, follows the symmetry of the central nave. In the cloister buildings of the old prelature, which were re-built in a baroque style during 1660-1668 by Giovanni Domenico Orsi, there are early baroque stuccos in the ground rooms. In the 18th century Karlov became a place of pilgrimage. Interior of the church was adapted architectonically and underground Bethlehem cave and so-called Holy stairs were built. Also a picture of the Virgin Mary of Karlov by Jan Jiří Heintsch was placed there. The copy was made by Josef Vojtěch Hellich. The picture is unique as the Virgin Mary is presented as pregnant in it. The cloister was abolished in 1784 and after building adaptation it was used as a hospice and workhouse, later on as a branch of the local sanitary facilities. Nowadays, since 1991, Museum of Police of the Czech Republic has its seat there. The interesting exhibition is open to public. Idyllic character of this place, which is slightly aside the main tourist movement, has been intensified by a small preserved and fenced park and an isolated chapel. In the alcove of this tiny building there is placed a statue of Emperor Charles IV by Josef Max from 1837. Below tympanum there is a laudatory inscription saying: „Charles the Fourth Father of the Czechs“. This area can be easily accessed by the underground of route C to the station of Vyšehrad, then by a walk over the Nusle Bridge, where you can view cupolas and towers of Karlov and historic and modern Prague.
