EN
The siege of Zbaraż as well as the battles fought outside the fortress between the 10 th and 25th of August 1649 left a prominent and indelible mark of Polish historiography. It is still an undeniable example of heroism, courage and devotion of its defenders. Despite justifed reservations expressed about the campagin preparations, Zbaraż might be perceived in an utterly differnet light. The persistent defence of the fortress gave the king priceless time to mobilize the royal forces and lead his army to the Ukraine. What deserves special attention is the exceptional role of Jeremi Wisniowiecki who rendered considerable services as an informal commander in the defence of Zbaraż. Preserved until this day diaries, letters and, above all, journals, allow historians to reconstruct the course of events in those times. The above presented material is the first part which depicts the combat for holding out the fortress in July and which closes the first stage of its defence.