After securing his "favorite" victory in the Battle of Holowczyn, despite being outnumbered over three to one by the new Russian army, Charles opted to march eastwards on Moscow rather than try to seize Saint Petersburg, founded from the Swedish town of Nyenskans five years earlier. Peter the Great managed, however, to ambush Lewenhaupt's army at Lesnaya before Charles could combine his forces, thus losing valuable supplies, artillery and half of Lewenhaupt's men. Charles' Polish ally, Stanisław Leszczyński, was facing internal problems of his own. Charles expected the support of a massive Cossack rebellion led by Mazepa in Ukraine, with estimates suggesting Mazepa was able to muster about 40,000 troops. However, the Russians subjugated the rebellion and destroyed its capital, Baturin, before the arrival of the Swedish troops. The harsh climate took its toll as well, because Charles marched his troops to winter camp in Ukraine.