Anhalt-Harzgerode was a principality and member of the Holy Roman Empire

Holy Roman Empire

The Holy Roman Empire was a realm that existed from 962 to 1806 in Central Europe.It was ruled by the Holy Roman Emperor. Its character changed during the Middle Ages and the Early Modern period, when the power of the emperor gradually weakened in favour of the princes...

. It was created in 1635 following the partition of Anhalt-Bernburg

Anhalt-Bernburg

Anhalt-Bernburg was a principality of the Holy Roman Empire and a duchy of the German Confederation ruled by the House of Ascania with its residence at Bernburg in present-day Saxony-Anhalt...

 with Frederick, a younger son of Christian I becoming the reigning prince. The death Prince Frederick's son William Louis in 1709 resulted in the extinction of the ruling family and Anhalt-Harzgerode was reunited with Anhalt-Bernburg.

Princes of Anhalt-Harzgerode

• Frederick
  Frederick, Prince of Anhalt-Harzgerode
  Frederick of Anhalt-Harzgerode , was a German prince of the House of Ascania and the first ruler of the principality of Anhalt-Harzgerode....
  
   1635-1670
• William Louis
  William Louis, Prince of Anhalt-Harzgerode
  William Louis of Anhalt-Harzgerode , was a German prince of the House of Ascania and the last ruler of the principality of Anhalt-Harzgerode....
  
   1670-1709

To Anhalt-Bernburg