The Russian armies retreated continuously, dispersing the cattle and hiding the grain in the peasant towns they passed, burning unharvested crops, and leaving no resources for the Swedish army to stave off the Russian winter. By the end of the winter of 1708–1709, the "Great Frost of 1709" had devastated the Swedish army and shrunk it to 24,000 men. In May 1709, the Swedish forces caught up to the Russians, and the two armies clashed in the Battle of Poltava.