After this he was chiefly occupied with foreign affairs, and he soon became one of the most conspicuous figures in German politics. He was the leader of that party which hoped to maintain the independence of the smaller states, and was the opponent of all attempts on the part of Prussia to attract them into a separate union. In 1849-1850 he was compelled to bring Saxony into the "three kings' union" of Prussia, Hanover and Saxony, but he was careful to keep open a loophole for withdrawal, of which he speedily availed himself. In the crisis of the Erfurt Union, Saxony was on the side of Austria, and he supported the restoration of the diet of the German Confederation.