Had the Cossacks stayed at Khortytsia, they might have been defeated, as in many other rebellions. However, Khmelnytsky marched against the Poles. The two armies met on 16 May 1648 at Zhovti Vody, where, aided by the Tatars of Tugay Bey, the Cossacks inflicted their first crushing defeat on the Commonwealth. It was repeated soon afterwards, with the same success, at the Battle of Korsuń on 26 May 1648. Khmelnytsky used his diplomatic and military skills: under his leadership, the Cossack army moved to battle positions following his plans, Cossacks were proactive and decisive in their manoeuvrers and attacks, and most importantly, he gained the support of both large contingents of registered Cossacks and the Crimean Khan, his crucial ally for the many battles to come.