In the Seven Years' War (1756–63) French troops were holed up here for seven weeks after losing the Battle of Grebenstein; two dugouts on the slopes of the Heiligenberg remain as a reminder of their camp.
Hermann II, called "the Learned", was born in 1345 in Grebenstein castle, the son of Louis the Junker.
##Count Karl Victor Adolph of Westarp (b. Grebenstein, 6 April 1796 - d. Hamburg, 4 May 1850); married in Berlin on 23 June 1822 to Baroness Pauline of Müffling (b. Erfurt, 17 November 1803 - d. Potsdam, 15 May 1886).
Wilhelm Friedrich Philipp Pfeffer (9 March 1845 - 31 January 1920) was a German botanist and plant physiologist born in Grebenstein.