Siegfried I Blankenburg Regenstein and Count of

Siegfried I Blankenburg was born about 1120 in Regenstein.  Siegfried I Blankenburg's father was Poppo I Of Regenstein Count and his mother is Rixa Of Northeim Countess.  His paternal grandfather was Siegfried Of Regenstein Count.  He was an only child.  He died after 1172.  He was buried after 1182.

He had two biological sons named Heinrich I and Siegfried II.