as a result, in the eastern territories a polish (or polonized) aristocracy dominated a peasantry whose great majority was neither polish nor catholic. moreover, the decades of peace brought huge colonization efforts to nowadays ukraine, heightening the tensions among nobles, jews, cossacks (traditionally orthodox), polish and ruthenian peasants. the latter, deprived of their native protectors among the ruthenian nobility, turned for protection to cossacks that facilitated violence that in the end broke the commonwealth. the tensions were aggravated by conflicts between eastern orthodoxy and the greek catholic church following the union of brest, overall discrimination of orthodox religions by dominant catholicism, and several cossack uprisings. in the west and north, many cities had sizable german minorities, often belonging to lutheran or reformed churches. the commonwealth had also one of the largest jewish diasporas in the world – by the mid-16th century 80% of the world's jews lived in poland ("pic. 16").