The Khmelnytsky Uprising, by far the largest of the Cossack uprisings, proved disastrous for the Commonwealth. The Cossacks, allied with the Tatars, defeated the forces of the Commonwealth in several battles, the Commonwealth scored a major victory at Berestechko, but the Polish-Lithuanian empire ended up "fatally wounded". The easternmost parts of its territory were effectively lost to Russia, which resulted in a long-term shift in the balance of power. In the short-term the country was weakened at the moment of the invasion by Sweden.