But what the Polish stipends signally failed to do was to stop the Cossacks attacking Poland herself. A series of uprisings – in 1591, 1595, 1625, 1635 and 1637 – was met with equally vicious pacification campaigns, culminating in 1648 with the biggest and bloodiest Cossack rebellion of them all, under Hetman Bohdan Khmelnytsky.
