Werner was the eldest son of Lothair I, Margrave of the Nordmark, and his wife Godila of Rothenburg, a Franconian.
Werner abducted Liutgard, the eldest child of Eckard I of Meissen, from the castle of Quedlinburg and, in January 1003, married her.
That same year, Werner succeeded his father in the Nordmark, but was removed from office and deprived of his titles in 1009 following accusations brought forth by Dedo I, Count of Wettin.
Werner, accompanied by his cousins Henry and Frederick, abducted Reinhild, the "mistress of Beichlingen," in November 1014.
He was captured, but before he could be put on trial, was murdered at Allerstedt on 11 November 1014, "having patiently endured whatever misfortunes had hitherto come his way", according to Thietmar.