The war came as a result of Croatian, Slavonian and Hungarian noble diets electing different candidates for their kings, following the death of Louis II of Hungary at Battle of Mohacs.

Following the death of Louis II at the Battle of Mohacs, Croatian nobles gathered at Cetingrad in early 1527 in order to discuss the election of a new king.

Habsburg commanders soon successfully captured the towns of Győr, Komárom, Esztergom, Visegrád and Buda, while Zapolya's forces retreated towards river Tisza.

As he was scouting for weakpoints in town walls, a defending cannon opened fire and one of the missiles gravely wounded Frankopan.

Dying Frankopan issued orders to carry on with the siege, however majority of the army he assembled began dispersing irretrievably.