Regenstein

The Saxon comital House of Regenstein took its name from Regenstein Castle north of Blankenburg on the edge of the Harz. Its progenitor Count Poppo I of Blankenburg was first documented as a count in 1128 in the service of Duke Lothair of Supplinburg. Poppo's son Conrad first styled himself Count of Regenstein in 1162, while another son, Siegfried, kept Blankenburg.

Early in the fourteenth century the family acquired Heimburg Castle. In 1343 the Regenstein-Heimburg line reunited the Regenstein and Blankenburg lands under Count Albert II, who had feuded with the Bishops of Halberstadt and Abbesses of Quedlinburg since the 1330s and was murdered on the orders of Bishop Albert II of Halberstadt.

In the fifteenth century the family moved its seat to Blankenburg and abandoned Regenstein to ruin. It adopted Protestantism in 1539 and died out with Count John Ernest in 1599, when the county reverted to the Prince-Bishopric of Halberstadt.