Surrounded by German territories north, west, and south of Poland, the Poles had little space for tactical retreat. The Germans reached Warsaw and attacked on September 7, but were repulsed suffering heavy tank losses and were forced to retreat. The Battle of Bzura on September 9 was the largest attack by the Poles during the war. The Poles had great initial success, decimating 2 German divisions and took 3500 German prisoners. Polish infantry fought well, but by September 19th, due to overwhelming German reinforcements, they were defeated.