Since France had been defeated on these two fronts, states that had been conquered and controlled by Napoleon saw a good opportunity to strike back. The Sixth Coalition was formed under British leadership. The German states of the Confederation of the Rhine switched sides, finally opposing Napoleon. Napoleon was largely defeated in the Battle of the Nations outside Leipzig in October 1813, his forces heavily outnumbered by the Allied coalition armies and was overwhelmed by much larger armies during the Six Days Campaign (February 1814), although, the Six Days Campaign is often considered a tactical masterpiece because the allies suffered much higher casualties. Napoleon abdicated on 6 April 1814, and was exiled to Elba.