Gladbach Abbey was a Benedictine abbey founded in 974 by Archbishop Gero of Cologne and the monk Sandrad from Trier. It was named after the Gladbach, a narrow brook that now runs underground. The abbey and its adjoining villages grew into the town of Gladbach, incorporated in the 1360s, the origin of the present city of Mönchengladbach in North Rhine-Westphalia.
In 1802 the abbey was occupied by troops under the French occupation and secularised; its great library was dispersed. From 1805 to 1835 it was used as a textile mill.
In 1835 the city authorities acquired the main building to replace the old Rathaus, which was demolished. This now constitutes the present Rathaus Abtei. The remaining monastic buildings were also acquired by the city one by one, for the accommodation of municipal offices.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.