He was the eldest son of Margrave
Ottokar I of Styria and his wife Willibirg of
Eppenstein, possibly a daughter of Duke
Adalbero of Carinthia. He succeeded as margrave upon the death of his father in 1075. Like his father, Adalbero sided with Emperor
Henry IV in the fierce
Investiture Controversy, which led to a confrontation with his younger brother
Ottokar II, an ally of
Pope Gregory VII. In 1082 Adalbero finally was forced to resign in favour of his brother and was killed shortly afterwards.