and their allies, who were assembled at the Congress of Vienna, declared Napoleon an outlaw, and with the signing of this declaration on 13 March 1815, so began the War of the Seventh Coalition. The hopes of peace that Napoleon had entertained were gone – war was now inevitable. A further treaty (the Treaty of Alliance against Napoleon) was ratified on 25 March in which each of the Great European Powers agreed to pledge 150,000 men for the coming conflict. Such a number was not possible for Great Britain, as her standing army was smaller than the three of her peers. Besides, her forces were scattered around the globe, with many units still in Canada, where the War of 1812 had recently ceased. With this in mind she made up her numerical deficiencies by paying subsidies to the other Powers and to the other states of Europe that would contribute contingents. Some time after the allies began mobilising, it was agreed that the planned invasion of France was to commence on 1 July 1815, much later than both Blücher and Wellington would have liked as both their armies were ready in June, ahead of the Austrians and Russians; the latter were still some distance away. The advantage of this later invasion date was that it allowed all the invading Coalition armies a chance to be ready at the same time. Thus they could deploy their combined numerically superior forces against Napoleon's smaller, thinly spread forces, thus ensuring his defeat and avoiding a possible defeat within the borders of France. Yet this postponed invasion date allowed Napoleon more time to strengthen his forces and defences, which would make defeating him harder and more costly in lives, time and money. Napoleon now had to decide whether to fight a defensive or offensive campaign. Defence would entail repeating the 1814 campaign in France but with much larger numbers of troops at his disposal. France's chief cities, Paris and Lyon, would be fortified and two great French armies, the larger before Paris and the smaller before Lyon, would protect them; francs-tireurs would be encouraged, giving the Coalition armies their own taste of guerrilla warfare. Napoleon chose to attack, which entailed a pre-emptive strike at his enemies before they were all fully assembled and able to co-operate. By destroying some of the major Coalition armies, Napoleon believed he would then be able to bring the