Dietrich was the only son of Count
Dedo I, Count of Wettin and his wife Thietburga, a daughter of Count
Dietrich of Haldensleben, the first
margrave of the
Northern March. Dietrich II thereby was a grandson of the Wettin progenitor
Theodoric I. At Christmas 1009, after his father was killed in a fierce struggle with Margrave
Werner of the Northern March, Dietrich was vested with the County of
Wettin in the Saxon
Hassegau by King
Henry II of Germany at
Pöhlde. From 1015, he also appeared as a and count in the neighbouring
Schwabengau. Upon the death of his uncle Frederick I, who had died without male issue in 1017, Dietrich inherited
Eilenburg and
Brehna. In 1018, Dietrich II and his brother-in-law, Margrave
Herman I of Meissen acted as witnesses when the
Peace of Bautzen was concluded between Emperor Henry II and the
Polish ruler
Bolesław I the Brave, ending a lengthy
German–Polish War. From 1029, Emperor
Conrad II again waged war against Poland. Bolesław's son and successor
Mieszko II lost Lusatia and finally had to renounce his claims in the 1033
Treaty of Merseburg. According to the
Annalista Saxo chronicles, Dietrich played a key role in the emperor's campaign and in turn could succeed the Lusatian margrave
Odo II in 1032. However, Dietrich earned the hatred of his brother-in-law
Eckard II of Meissen and was killed by his henchmen, whereby Eckard became his successor in
Lusatia. Dietrich II's possessions were divided among his sons. As Count of Eilenburg, he was succeeded by his eldest son
Dedi, who also became Margrave of Lusatia upon the death of Margrave Eckard II of Meissen in 1046. ==Marriage and issue==