Lothair Udo III (1070-1106), Margrave of the Nordmark and Count of Stade (as Lothair Udo IV), son of Lothair Udo II, Margrave of the Nordmark, and Oda of Werl, daughter of Herman III, Count of Werl, and Richenza of Swabia.
Eilika moved on and married Otto the Rich, Count of Ballenstedt, and was mother to Albert the Bear, the last Margrave of the Nordmark and first Margrave of Brandenburg.
Lothair Udo and Irmgard had four children: Lothair Udo was succeeded by his brother Rudolf as margrave and count upon his death.
Hucke, Richard G., Die Grafen von Stade.
Genealogie, politische Stellung, Comitat und Allodial- besitz der sächsischen Udonen, Selbstverlag des Stader Geschichts und Heimatvereins, Stade, 1956 Raffensperger, Christian, Reimagining Europe, Harvard University Press, Cambridge, MA, 2012