Voltaire discussed Ukraine and its ruler Ivan Mazepa in two of his historical works. In his 1731 history of Charles XII of Sweden, he described how Charles turned to Ukraine for supplies after defeats in Poland, hoping for an alliance with Mazepa against Russia. Voltaire portrayed Ukraine as aspiring to freedom but forced to seek protection from Poland, Turkey, or Russia, and having its autonomy reduced over time. In his 1761 history of Peter the Great's Russian Empire, Voltaire focused more on Peter's reforms but still mentioned Mazepa's revolt against Russian rule. His treatment of Ukraine and Mazepa differed in emphasis between the two works due to their different subjects and time periods.