The County of Regenstein was a mediaeval statelet of the Holy Roman Empire.
County of Regenstein Wikipedia
The counts of Regenstein Castle near Heimburg were first mentioned in an 1169 deed, with Count Conrad of Regenstein, son of Poppo I, Count of Blankenburg (1095–1164), himself a nephew of Count Reinhard, Bishop of Halberstadt from the Ripuarian House of Reginbodo.
The most renowned Count of Regenstein was Albert II (1310–49), who in the 1330s was frequently in dispute with the leaders of the surrounding estates like the Halberstadt bishops and the abbess of Quedlinburg. These tales were romanticised in the ballad The Robber Count (German: Der Raubgraf) by Gottfried August Bürger, melodized by Johann Philipp Kirnberger and the novel of the same name by Julius Wolff.
In the 15th century the comital family relocated its seat to Blankenburg; Regenstein Castle lapsed and was left to ruin. The last scion of the comital family, Count John Ernest, died in 1599. With Blankenburg it fell back to the Bishopric of Halberstadt. Shortly thereafter Blankenburg and Regenstein were separated. Regenstein remained with Halberstadt, while Blankenburg was annexed and held by the Dukes of Brunswick-Wolfenbüttel.Siegfried (-1073), brother of Konrad, Count of Blankenburg-Regenstein
Henry (-1235), son
Siegfried II (-1251), son
Ulric, Count of Regenstein-Heimburg (-1267), brother
Ulric III (1287–1322)
Albert II (1310–1349), son
Albert III (1341–1365), son
John Ernest, Count of Blankenburg and Regenstein (-1599)