As the "unia" continued its expansion into Ukraine, its unpopularity grew, particularly in the southern steppes where Dnieper Cossacks lived. The Cossacks, who valued their traditions and culture, saw the "unia" as a final step of Polonization. As a result, they reacted by becoming fierce proponents of Orthodoxy. Such feelings played a role in the mass uprising whose targets included all non-Orthodox religious proponents, the Catholic and Uniate clergy and Jews. During this time metropolitan Mogila took full advantage of the moment to restore the Orthodox domination in Ukraine, including returning one of its sacred buildings, the Saint Sophia Cathedral in Kyiv.