The monastery was founded in 1286 by the margraves of Brandenburg, Otto IV and Konrad, from the older line of the Askan dynasty. The time of creation of the oldest part of buildings can be determined for the years between 1294 and 1326. It was a period of the best economic situation for the monastery. The end of the monastery’s peace was laid in 1326 by Władysław Łokietek’s armed expedition against Louis V of Bavaria. As a result of hostilities and the plague that accompanied it, many of the New March settlements were completely deserted. The monastery was robbed, the buildings burnt down, and the Cistercians for many years could not get out of the state of economic collapse. A slow improvement of the situation took place only in the second half of the 14th century, thanks to the help of the monastery in Kołbacz and margraves of Brandenburg.
In 1539, margrave John of Kostrzyn carried out the secularization of the abbey, and a complex of monastery buildings became part of the state domain. The abbot church lost its sacral function and was slowly devastated. The abbey also suffered during the military operations of the Thirty Years War. Finally, in the first half of the 17th century, a summer residence of the Brandenburg electors was arranged in the preserved monastic buildings. Another loss brought to the buildings of the abbey, a fire from the beginning of the 19th century, in which the western part of the church was completely destroyed, and the chancel was severely damaged.
The monastery church was devoid of transept, a three-nave, hall structure. Its nave was eight spans long and was ended with an apse, preceded by a rectangular span, while at the end of the side aisles, were rectangular chapels. The monastic buildings were built to the south of the church. They consisted of three wings closing the inner patio and connected by cloisters with cross-ribbed vaults. Economic buildings were located to the south of the monastery, including a brewery from the fourteenth century. It was made of brick and stone on a rectangular plan, reinforced with buttresses in corners and covered with a gable roof based on triangular gable walls, decorated with pointed blendes.
The relics of the medieval monastic complex preserved to this day, do not reflect the former splendor of the seat of the Cistercians of Bierzwnik. From the former church survived the transformed eastern part, which consists of a polygonal choir and adjacent to it two spans of the former nave. The part of the nave located further west, has been almost completely destroyed. To this day only the external wall of the southern aisle has survived to the height of 3-4 meters. Of the monastic buildings survived: a single storey of the east and south wings, as well as fragments of the basements of the west wing and elements of the western cloister.
Pilch.J, Kowalski S., Leksykon zabytków Pomorza Zachodniego i ziemi lubuskiej, Warszawa 2012.
Webpage bierzwnik.pl, Klasztor pocysterski w Bierzwniku.