Discussing about the situation at a session of the Croatian Parliament on 26 July 1591, the nobles concluded that in the case of a large scale invasion, a general uprising was to be called, and that all the nobles and citizens, as well as their subordinates, should answer the call.[22] On 1 August 1591 Hasan Pasha attacked Sisak. The city's position was crucial as it defended the left bank of the Kupa River, but also the approach to Zagreb. Upon hearing of the siege of Sisak, Ban Thomas Erdődy sent help to the city and Hasan Pasha was forced to retreat on 11 August.