 In 1637 Wiśniowiecki might have fought under Hetman Mikołaj Potocki against the Cossack rebellion of Pavel <unk> ( the <unk> Uprising ) ; Jan Widacki notes that historians are not certain whether he did and in either case , no detailed accounts of his possible participation survive . A year later , returning from the Sejm and from the engagement ceremony with Gryzelda , he gathered a 4 @,@ 000 strong division that participated in putting down of the <unk> Uprising and arrived at the region affected by the unrest in June that year . Together with Hetman Potocki he defeated the insurgents at the Battle of <unk> , which turned into a rather difficult siege of the Cossack camp that lasted from 13 June till the Cossack relief forces were defeated on 4 August , and the Cossacks <unk> on 7 August . 
