Tough Imperial troops fresh from savage fighting in the Low Countries have come under the supreme command of the Styrian general Ruprecht von Eggenberg.

Their crushing defeat of the Ottoman troops of Bosnian governor-general, or Beylerbeyi, Hasan Pasha Predojević at Sissek (Sisak) on June 22, 1593, enlarges the hostilities into a full-scale war.

Croatian troops are led by the Ban of Croatia, Tamás Erdődy, and some forces from the Duchy of Carniola are led by Andreas von Auersperg (Slovene: Andrej Turjaški), nicknamed the "Carniolian Achilles".

Recent analysis of several hitherto unknown or unused Ottoman sources has shown that there seems to have been a conflict of interest between the policy of the central Ottoman administration and the aims of the belligerent Hasan Pasha.

It appears that the struggle for more land and power was an important incentive for the offensive action on the side of the Bosnian sipahis, an action which at this time is not really in accordance with Constantinople’s policy.

The Sultan, on the other hand, may have felt that such an embarrassing defeat even of a vassal acting independently could not go unavenged if he himself was not to lose face.