[1] Although Azzo II of Este continued firm in the interests of Pope Gregory VII, Welf's marriage, and his inheritance of property in Germany, meant that he was more concerned with German affairs and he supported Emperor Henry IV.

In compliance with Henry's commands, he repudiated and divorced his wife, Ethelinde,[2] [3] and soon thereafter (in 1070) he was rewarded for his fidelity by being appointed Duke of Bavaria in Otto's stead.

[4] This event took place at Goslar in 1070, when the Duchy of Bavaria submitted quietly to the newly made duke, who was the representative of one of the most ancient families in the province.

Henry, in consequence of these repeated acts of rebellion, declared Welf deposed in his newly acquired duchy.

However, supported by his faithful Bavarians and aided by his father in Italy, Welf was able to maintain his place, and openly defy the ban of the Empire in May 1077.