Schloss Leitzkau / Sancta Maria in Monte

After the Slavs were defeated, Leitzkau became a base for Christian missions. In 1114, the bishop of the Brandenburg diocese had a stone church of St. Petri built and appointed Leitzkau as the provisional seat of the diocese in place of the cathedral chapter in Brandenburg that had been destroyed and occupied by the Slavs in 983.

In 1133 a Premonstratensian monastery was established here with the task of missionizing the areas. Three years later, the Bishop of Brandenburg took up his seat in Leitzkau, which was temporarily given the status of a cathedral chapter. After St. Peter's Church no longer met the requirements despite an extension in 1140, the bishop ordered the construction of a new collegiate church in 1147. The three-nave basilica "Sancta Maria in Monte" was inaugurated in 1155.

Just ten years later, Leitzkau lost his position after the destroyed cathedral chapter in Brandenburg had been restored. The monks' convent then quickly fell into poverty and had to sell the monastery property.

In 1535, as a result of the Reformation, the Brandenburg Elector Joachim II decreed the dissolution of the monastery. In 1564 the buildings were sold to the colonel and mercenary leader Hilmar von Münchhausen.

He began to convert the existing Romanesque buildings, some of which had already fallen into disrepair, for his purposes. A rectangular palace complex was formed from the former convent building. The monastery church was rebuilt into the castle church, whereby the side aisles and the chancel were demolished and the transept was converted into a granary, the north tower was shortened by half. Hilmar's son Statius increased the eastern wing of the convent to the so-called "Althaus" and had the cloister walled up, while he rebuilt the "Neuhaus" on the foundations of the western wing of the convent from 1593.

Since father Hilmar and son Statius had already erected several Renaissance buildings in the Weser-Ems area, in particular Schwöbber, the new and old houses were also built in this style, using local stonemasons and master builders; Leitzkau is considered an eastward shifted Weser Renaissance “island” in the middle of the Saxon Renaissance area. By 1600, the former monastery of canons was transformed into a Renaissance castle.