The Saxon fortress of hahaldeslevo in Eastphalia was first mentioned in a 966 deed of donation issued by Emperor Otto I.

The Counts of Haldensleben rose to considerable power, most notably Dietrich and William, who ruled as margraves of the Northern March.

Besieged and devastetd by the forces of Archbishop Wichmann in 1181, the Haldensleben estates belonged to the Prince-Archbishopric of Magdeburg from 1215.

The Protestant Reformation was implemented in 1541 and in 1680 the former episcopal lands were secularized as the Duchy of Magdeburg, held by the Hohenzollern rulers of Brandenburg-Prussia.

Nearby Hundisburg Castle was owned by the House of Alvensleben from 1452 until 1811, enlarged in baroque style, with formal gardens, by Hermann Korb from 1693 on the order of Johann Friedrich II.