 A notable magnate and military commander with Ruthenian and Romanian origin , Wiśniowiecki was heir of one of the biggest fortunes of the state and rose to several notable <unk> , including the position of voivode of the Ruthenian <unk> in 1646 . His conversion from Eastern <unk> to Roman Catholicism caused much dissent in Ruthenia and Ukraine ( parts of the Polish – Lithuanian Commonwealth ) . Wiśniowiecki was a successful military leader as well as one of the wealthiest magnates of Poland , ruling over lands inhabited by 230 @,@ 000 people . 
