(Ludwig Friedrich) Leopold von Gerlach was a Prussian army general, adjutant to King Frederick William IV of Prussia and a Protestant conservative associate of Otto von Bismarck.

Frederick William IV, the eldest son and successor of Frederick William III of Prussia, was king of Prussia from 7 June 1840 until his death on 2 January 1861. Also referred to as the "romanticist on the throne", he was deeply religious and believed that he ruled by divine right. He feared revolutions, and his ideal state was one governed by the Christian estates of the realm rather than a constitutional monarchy.