According to the cronicles of Corvey Abbey a haanstedihus was given to one Eilhard between 826-853. The chronicler Lambert of Hersfeld mentioned the destruction of Burg Hanenstein, then in possession of Saxon Count Otto von Northeim, by King Henry IV in 1070. The castle was inherited by the House of Welf and in 1203 it was in the possession of Count Palatine Henry V, then of his brother Emperor Otto IV, who in 1209 granted it to the Archbishopric of Mainz.
In 1308, Heinrich and Lippold von Hanstein with the permission of Bishop Peter of Aspelt began to re-build the whole of the castle. The walls and gates destroyed during the Thirty Years' War were re-built between 1655 and 1658. In 1840, the building of a new hall for family conferences was being finished.
Massive renovations between 1904 and 1907.
In 1946, Hanstein Castle became the property of the German Democratic Republic. Due to the fact that the border was only several hundred meters away one of the towers was used by the border guard as a watch tower. Some renovations started in 1985, although no tourists were allowed to go to the castle, because of the border.
The castle today
Since 1990, Hanstein Castle belongs to the municipal council of Bornhagen. English photographer Mark Robert Davey helped the castle in 2006 by raising money with his black and white photograph of the Hanstein. In 2008, Hanstein Castle celebrates 700 years. Various festivals are taking place every year.