The Battle of Warsaw took place near Warsaw on July 28–July 30 [O.S. July 18–20] 1656, between the armies of the Polish–Lithuanian Commonwealth and Sweden and Brandenburg. It was a major battle in the Second Northern War between Poland and Sweden in the period 1655–1660, also known as The Deluge. According to Hajo Holborn, it marked "the beginning of Prussian military history".