Peter Orseolo, who had been deposed by Samuel Aba in 1041, returned with the assistance of Emperor Henry III, and invaded Hungary in June 1044.

However, there was disaffection in the Hungarian ranks and the army quickly fell apart in the face of the German cavalry.

Peter was reinstalled as king at Székesfehérvár and did homage for his kingdom to Henry.

The leading magnates and the less important nobles all came to Henry to make oaths of fidelity and vassalage.

Hungary was made a vassal of the Holy Roman Empire, though it was not to remain so for long.