During Agnes' regency, the Princes of the Holy Roman Empire could further strengthen their position against the Imperial authority. In the 1062 Coup of Kaiserswerth, several princes led by Archbishop Anno II of Cologne even abducted the minor king to enforce the surrender of the Imperial Regalia. When Henry came of age in 1065, he continued the policies of his father against the reluctant Saxon nobility, sparking the Saxon Rebellion in 1073. While other princes like the Carinthian duke Berthold of Zähringen or Duke Welf of Bavaria distanced themselves, Rudolf supported Henry's campaigns in Thuringia, when he was a primary force in the 1075 Battle of Langensalza against the insurgents. However, after the joint victory, Rudolf became estranged to the king and rumours occurred that he was involved in adversarial conspiracies. Empress Agnes repeatedly had to arbitrate between the parties.