Doorn Castle, locally known as Huis Doorn, lies in the town of Doorn, in the Utrecht province in the Netherlands.
Doorn Castle was first mentioned in 838 as 'Villa Thorhem' in an ecclesiastical property. This 'Villa Thorhem' probably wasn't a real castle but an estate governed by a dean. It is assumed that the first real castle at this site was built at the end of the 13th century by a dean, either Borchard van Henegouwen or Adolf van Waldeck. This first castle was rectangular with 3 round corner towers and a gate tower at the fourth corner.
The dean lived as a noble on Doorn Castle which angered the Bishop. So, in 1322, Doorn Castle was destroyed by the Bishop with the help of Willem III, Count of Holland. A new dean, Hendrik van Mierlaer, rebuilt the castle in 1347 with permission of the Bishop. This new castle consisted of several buildings centered around a courtyard. At the east this was secured by a curtain wall and in the north west stood a keep built against the round corner tower. Furthermore it had a gate building at the north side and a bailey.
In the first half of the 17th century Doorn Castle was rebuilt by Reynier van Golsteyn after it had fallen to ruin.
In the first half of the 18th century Doorn Castle was probably rebuilt; one tower was torn down, another was heightened, the curtain wall was lowered and the keep was modernized. In 1792 the castle was bought by the widow Wendela Eleonora ten Hove, Lady of Doorn, Den Bosch and Sleeburg. At that time the castle still had its medieval ground plan. She rebuilt the castle into a U-shaped mansion in the style of the Neo Renaissance.
Several other owners followed until Doorn Castle was bought in 1919 by the German Emperor, Wilhelm II, who had been granted asylum in The Netherlands after World War I. He made his castle a real residence by bringing 34 wagon loads of furniture and other personal belongings to the castle, coming from all his castles and palaces in Germany. Wilhelm II lived at Doorn Castle until his death in 1941 after which his remains were set in a mausoleum on the estate. After his death the castle became a Hohenzollern museum. At present the castle is still a museum but mainly about Wilhelm II.