Dietrich (11th century), Count of Plötzkau', son of Bernhard I von Kakelingen, Count of Harzgau and his wife Ida of Querfurt.
Dietrich was the brother of Gebhard of Supplinburg, a Saxon count, who was the father of Lothair II, Holy Roman Emperor.
Ida, the mother of Dietrich, was niece of Saint Bruno of Querfurt.
Hucke, Richard G., Die Grafen von Stade.
Genealogie, politische Stellung, Comitat und Allodialbesitz der sächsischen Udonen.