The monastery was founded by prince Casimir the Restorer in the second half of the 11th century. The Benedictines were then brought to a settlement founded two centuries earlier on a peninsula cutting into Lake Mogilno. The monks came from the Rhineland and Bavaria, and the monastery received large grants. The construction of church and monastery buildings began immediately after the arrival of the monks.
The monastery was rebuilt in the late romanesque style, after the destruction by the army of prince Władysław Odonic and the conflict of monks with prince Władysław Laskonogi in the first half of the 13th century. In the fifteenth century, another reconstruction was made, which gave the monastery gothic features.
In subsequent centuries, the political role of the monastery fell, and buildings were also destroyed. It was not until the eighteenth century that the Benedictine community began to flourish again and rebuilt the monastery complex in the baroque style that took place in 1760-1797. In 1773, after the first partition of Poland, Mogilno was under Prussian rule, and the new authorities took over the monastery property. In 1833, the monastery was completely closed, and the buildings were given to local Catholics and Protestants for school. After 1880, the monastery housed a hospital, whereby the church still served as a parish. In 1934, the renovation was carried out, while during the Second World War German Nazis placed in it a transit camp, a prisoner-of-war camp, a prison for Jews, and a hospital. In the 1970s, archaeological and historical research was carried out at the monastery, and the building was renovated.
The monastery church was originally a three-span, three-nave basilica with a rectangular presbytery ended with an apse. The west façade was crowned with a square tower flanked by annexes being an extension of the side aisles. Romanesque parties are read in the lower zones of perimeter walls, crypts and foundations. In the endings of the aisles there were chapels ended with apses. In the 13th century, the presbytery was reconstructed with the use of bricks. The church is now covered with a gothic stellar vault in the central nave and diamond in the aisles. Under the church there is a complex of two rRomanesque crypts covered with a barrel vault: one under the presbytery and the other one under the western tower. The vault in the eastern crypt is not original, because it covers two side windows. Initially, the crypt could have a vault based on pillars or a higher-mounted barrel vault. The western crypt is one of the oldest preserved vaulted interiors in Poland.
The monastery buildings are three-winged, current buildings date from the sixteenth and seventeenth centuries. The southern wing houses the former abbot’s apartment, the refectory and the monastic kitchen; in the eastern wing there is a dormitory and rooms occupied by the service, and finally the western wing occupies auxiliary rooms. The whole was originally connected by a cloister. The monastery connects to the church, creating a closed quadrangle. There is an eleventh-century romanesque well, buried around the 15th century, with an original depth of about 14 meters.
Jarzewicz J., Kościoły romańskie w Polsce, Kraków 2014.
Website wikipedia.org, Klasztor Benedyktynów w Mogilnie.