The Altmark is located west of the Elbe river between the cities of Hamburg and Magdeburg, mostly included in the present-day[update] districts of Altmarkkreis Salzwedel and Stendal.
In the west, the Drawehn hill range and the Drömling depression separate it from the Lüneburg Heath in Lower Saxony; the Altmark also borders the Wendland region in the north and the Magdeburg Börde in the south.
They formed part of the Eastphalian territory of the Duchy of Saxony, which, from 843 onwards, constituted the eastern borderlands of East Francia under Louis the German.
In 936 the German king Otto I allotted the territory of the later Altmark to the Saxon Count Gero, in order to subdue the West Slavic Wends settling on the Elbe.
Upon Gero's death in 965, his marca was split and the Northern March was granted to Dietrich of Haldensleben, who nevertheless turned out to be an incapable ruler and lost all the territories east of the Elbe in the Slavic Lutici uprising of 983.
For more than one and a half centuries, the lands east of the Elbe defied German control, until in 1134 Emperor Lothair of Supplinburg bestowed the Northern March on the Ascanian count Albert the Bear.
After World War II the Altmark, lying to the east of the inner German border, became part of the new state of Saxony-Anhalt in the Soviet occupation zone.