The Herten family, vassals of the Werden Abbey, was first documented in 1286. At that time, their residence was probably in the center of today's city next to St. Antonius church. In the 14th century, the family with 'Ritter' (knight) status built a fortified house on the site of today's castle. In 1376, this building was mentioned as fief of Werden Abbey. Through marriage, the Herten house fell into the possession of the von Galen family in mid-14th century. In 1488, it changed hands in the same manner to Dietrich von Stecke zur Leythe. Ultimately, in 1529 Anna von Stecke married Betram I. von Nesselrode. As part of the powerful house of Nesselrode, he was steward for the Electorate of Cologne in the Recklinghausen district and expedited the modification and extension of the buildings in 1530.
While foundations of today's main castle building incorporate elements from the 14th-century building, the buildings visible today were built by Stecke and Nesselrode families in the 16th and 17th century. The main castle consists of four wings creating an inner courtyard.
After the First World War, the main castle building was no longer used as a residence and started to deteriorate. Subsidence caused by the widespread sub-surface mining in the surrounding industrial Ruhr area added to the structural damage, bringing the castle buildings close to collapse. Only radical restoration measures from 1974 to 1989 saved the late Gothic castle complex from total decline. Today it is used as a venue for concerts, cultural events and festivities. It also houses a café. The castle's park is popular for walking, picknicking, jogging and biking.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.