When his father was killed in 1034, Thimo succeeded him in his Wettin and Brehna home territories.

He also served as Vogt (bailiff) of the Naumburg diocese and of the Wettin family monastery in Gerbstedt.

In the Saxon revolt of 1073–1075, Thimo fought against King Henry IV and also quarreled with his brother Bishop Frederick of Münster.

Later he again approached the king and in 1088 attended the Hoftag diet in Quedlinburg, where the Brunonid margrave Egbert II of Meissen was deposed.

Thimo married Ida, daughter of Count Otto of Nordheim.