"the man who had devasted France returns"

 Napoleon's brief return is known as the Hundred Days, although in fact it lasted 111: from 20th March to 8th July 1815. After his exile to Elba, Napoleon raised an army and returned to re-conquer France while Britain, Russia, Prussia and Austria were thrashing out their differences at the Congress of Vienna, called to reorganise Europe in the wake of the earlier Napoleonic Wars. Napoleon marched on Paris and seized power again fairly quickly, aided by widespread dissatisfaction at the behaviour of the newly re-established monarchy and aristocracy. The Allies roused themselves, creating a huge army that met Napoleon for a final, decisive battle at Waterloo on 18th June 1815. Napoleon was forced to surrender shortly afterwards in Paris, and was re-exiled, this time to the far more distant island of St Helena, where he lived for the rest of his life.