The Catholic ruler of Saxony was one of the few German leaders to support the French. Saxony was put under Russian occupation and 40% of the Kingdom, including the historically significant Wittenberg, home of the Protestant Reformation, was taken by Prussia, but Frederick Augustus was allowed back to rule the remainder of his kingdom, which still included the major cities of Dresden and Leipzig. The Kingdom also joined the German Confederation, the new organization of the German states to replace the Holy Roman Empire.