Poppenburg Castle

Poppenburg Castle is located in the Lower Saxon town of Burgstemmen, above the Leine river and on Federal Highway 1. Strategically, in the Middle Ages, the hilltop castle dominated traffic on the old Hellweg between Aachen and Goslar, which was an important trade route from the Rhineland to Central Germany, due to its location on a hill above the Leine crossing. At times, the Leine river formed the border with the Diocese of Minden and later with the Principality of Calenberg. Poppenburg Castle was one of the old royal castles that protected the Leine valley and thus the route to the city of Hildesheim and the territory of the Prince-Bishopric of Hildesheim. The bridge near Poppenburg was first mentioned in a document on January 13, 1251. The exact time of the castle's construction is unknown. It was inhabited by the noble family of Poppenburg.

In 1049, Emperor Henry III gifted the estate (praedium) near Bobbenburg, which Duke Bernhard II of Saxony had ceded to him, to Bishop Azelin and thus to the Diocese of Hildesheim. At that time, the castle was located in the Gau Valen, in the county of a count named Bruno. Two years later (1051), Emperor Henry III transferred the county rights in six counties, including Gau Valen, to the Diocese of Hildesheim. Through this transfer, the castle came into the possession of the Diocese of Hildesheim. The Hildesheim Necrologium mentions at the death of Henry III: "Henricus imp. dedit dimidiam partem castelli Poppenburg ad praebendam fratrum".

Over the centuries, the castle complex was frequently expanded and renovated. Extensive construction measures took place in the 13th century, when the noble family of Poppenburg died out and the Prince-Bishopric of Hildesheim once again became the owner of Poppenburg Castle. In 1227, the castle was first mentioned in a document. Konrad II von Riesenberg, Bishop of Hildesheim (1221-1246), expanded Poppenburg Castle as a fortification during his tenure and enfeoffed it to Count Hermann von Wohldenberg in 1226. In 1240, the bishop succeeded in acquiring the Spiegelberg share of Poppenburg Castle; thereafter, he appointed Bodo von Ilten as Vogt (bailiff) for the administration of the episcopal share of the castle. The Vogt ensured that no unjust tolls were levied on the Leine bridge and that the wagon transports of merchants were not hindered. Konrad II and later Otto I von Braunschweig-Lüneburg, Bishop of Hildesheim (1260-1279), frequently stayed at the castle in the middle of the 13th century and issued documents there, as did Count Wedekind. Konrad II had a new residential wing built. The Bishops of Hildesheim became co-owners of the castle at this time; Count Wedekind could no longer act without their consent.

In the 14th century, Otto II von Woldenberg, Bishop of Hildesheim (1319-1331), took care of protecting Poppenburg Castle against fire hazards and had the residential building and the small tower covered with stone slabs. Gerhard von Berg, Bishop of Hildesheim (1365-1398), built the mighty residential tower-like palas in the south of the castle complex in 1367, after the feud with Magnus I, Duke of the Duchy of Braunschweig-Lüneburg from 1345 to 1369.

As a result of the Hildesheim Diocesan Feud, Poppenburg Castle fell to the Principality of Calenberg in 1523 and lost its strategic importance. Through the Hildesheim Main Recess of 1643, it returned to the Prince-Bishopric with the main part of the Great Diocese, which led to extensive renovation work on the castle complex. The castle church was recatholicized and remained the parish church for the surrounding villages until a modern new parish church was built in Nordstemmen in 1971.

In contrast to the palas, the residential wing of the castle is only two-story and has a narrow basic shape. The barrel and cross-rib vaults of the cellar system, the different construction methods in the roof truss, on the roof cornice, and the former half-timbered extension at the stair tower indicate that the residential wing was built in different construction phases. During the renovation and conversion measures after the Thirty Years' War, the building was consolidated into its current unit.

An inscription tablet with the year 1679 and the baroque courtyard entrance with the coat of arms of Elector Maximilian Henry of Bavaria (1650 to 1688) have been preserved.

The castle's floor plan from 1774 still shows, despite alterations, the enclosed castle complex with wall and keep. Under Prince-Bishop Friedrich Wilhelm von Westphalen, Bishop of Hildesheim from 1763 to 1789, the palace, formerly used as a brewery, was converted into a Catholic church. The flat-arched doors of the building bear the year 1785, the time of the conversion. During the conversion measures under Prince-Bishop Friedrich Wilhelm, the southern gatehouse, the keep, and part of the old castle wall were demolished. The broken stones obtained were used for the construction of the new brewery and the enclosing wall of a newly established vegetable growing operation.

Around 1790, a long half-timbered house was built on the foundation remains of the demolished castle wall. On the ground floor of the southern part were the magistrate's room and the prison cell, while the upper floor was assigned to the Catholic pastor as a residence. The northern half of the building, which projected into the castle courtyard, was used for economic purposes.

In 1903, Amtsrat Rudolf Koch had the residential wing extended with an altered axis direction and a tower-like annex.

In 1964, the Diakonische Werke Hildesheim bought the residential wing and the associated property with the castle courtyard and park. After extensive renovations of the residential building, demolition of the half-timbered annex and the half-timbered veranda on the lower floor, women with mild to moderate intellectual disabilities have been living here in house communities since 1967.

Since 2010, the castle church of St. Joseph belongs to the Catholic parish in Sarstedt.