Hartingowe in eastern Saxony about 1000 AD (19th century map)
The Harzgau was a medieval shire (Gau) in the northeastern foorhils of the Harz mountains, part of the Eastphalia region of Saxony.
It included the towns of Halberstadt, Quedlinburg, and Osterwieck, and was bounded by the Oker in the west, by the Großes Bruch swamps in the north, the Bode in the east, and the Harz range in the south. The county was bordered (clockwise) by the Salzgau, the Derlingau, the Nordthüringgau, the Schwabengau, the Thuringian Helmegau, and the Liesgau.
Counts in the Harzgau were:
Frederick I 875/880
Frederick II 937 and 945, son of Frederick I.
Volkmar I (d before 961), probably son of Frederick II.
Frederick III, son of Volkmar
Thietmar, Count in the Harzgau and Nordthüringgau, d 3 October 959
Frederick (d July 1002/15 March 1003), 995 to 996 count palatine in Saxony, Count in the Harzgau and Nordthüringgau
Liutger, 1013 Count, 1021 Count in the Harzgau, 1013 to 1031 (recorded) (Supplinburger family)
Bernard (d before 1069), 1052 Count in the Harzgau and Derlingau as well as North Thuringia, 1043 to 1062 (recorded), probably nephew of Liutger
^Habermann, Jan. Die Grafen von Wernigerode. Herrschaftsprofil, Wirkungsbereich and Königsnähe hochadliger Potentaten am Nordharz im späten Mittelalter. Norderstedt, 2008, p. 11