With social and political troubles thus awaking about them, even Tory statesmen were not willing to face the terrible consequences of a ruin of English industry, such as might follow from the junction of America with Napoleon. They were, in fact, preparing to withdraw the Orders in Council when their plans were arrested by the dissolution of the Perceval Ministry. Its position had from the first been a weak one. A return of the King's madness had made it necessary in the beginning of 1811 to confer the Regency by Act of Parliament on the Prince of Wales; and the Whig sympathies of the Prince threatened the Perceval Cabinet with dismissal. The insecurity of their position told on the conduct of the war; for the apparent inactivity of Wellington during 1811 was really due to the hesitation and timidity of the ministers at home. In May, 1812, the assassination of Perceval by a maniac named Bellingham brought about the fall of his ministry; and fresh efforts were made by the Regent to install the Whigs in office. Mutual distrust however foiled his attempts; and the old ministry was restored under the headship of Lord Liverpool, a man of no great abilities, but temperate, well informed, and endowed with a remarkable skill in holding discordant colleagues together.

The most important of these colleagues was Lord Castlereagh, who became Secretary for Foreign Affairs. His first work was to meet the danger in which Canning had involved the country by his Orders in Council. At the opening of 1812 America, in despair of redress, had resolved on war; Congress voted an increase of both army and navy, and laid an embargo on all vessels in American harbours. Actual hostilities might still have been averted by the repeal of the Orders, on which the English Cabinet was resolved, but in the confusion which followed the murder of Perceval the opportunity was lost. On the 23rd of June, only twelve days after the Ministry had been formed, the Orders were repealed; but when the news of the repeal reached America, it came six weeks too late. On the 18th of June an Act of Congress had declared America at war with Great Britain.

The moment when America entered into the great struggle was a critical moment in the history of mankind. Six days after President Madison issued his declaration of war, Napoleon crossed the Niemen on his march to Moscow. Successful as his policy had been in stirring up war between England and America, it had been no less successful in breaking the alliance which he had made with the Emperor Alexander at Tilsit and in forcing on a contest with Russia. On the one hand, Napoleon was irritated by the refusal of Russia to enforce strictly the suspension of all trade with England, though such a suspension would have ruined the Russian landowners. On the other, the Czar saw with growing anxiety the advance of the French Empire which sprang from Napoleon's resolve to enforce his system by a seizure of the northern coasts. In 1811 Holland, the Hanseatic towns, part of Westphalia, and the Duchy of Oldenburg were successively annexed, and the Duchy of Mecklenburg threatened with seizure. A peremptory demand on the part of France for the entire cessation of intercourse with England brought the quarrel to a head; and preparations were made on both sides for a gigantic struggle.

The best of the French soldiers were drawn from Spain to the frontier of Poland; and Wellington, whose army had been raised to a force of forty thousand Englishmen and twenty thousand Portuguese, profited by the withdrawal to throw off his system of defence and to assume an attitude of attack. Ciudad Rodrigo and Badajoz were taken by storm during the spring of 1812; and three days before Napoleon crossed the Niemen in his march on Moscow, Wellington crossed the Agueda in a march on Salamanca. After a series of masterly movements on both sides, Marmont with the French army of the North attacked the English on the hills in the neighbourhood of that town. While he was marching round the right of the English position, his left wing remained isolated; and with a sudden exclamation of " Marmont is lost!" Wellington flung on it the bulk of his force, crushed it, and drove the whole army from the field. The loss on either side was nearly equal, but failure had demoralized the French army; and its retreat forced Joseph to leave Madrid, and Soult to evacuate Andalusia and to concentrate the southern army on the eastern coast.

While Napoleon was still pushing slowly over the vast plains of Poland, Wellington made his entry into Madrid in August, and began the siege of Burgos. The town however held out gallantly for a month, till the advance of the two French armies, now concentrated in the north and south of Spain, forced Wellington in October to a hasty retreat on the Portuguese frontier. If he had shaken the rule of the French in Spain in this campaign, his ultimate failure showed how firm a military hold they still possessed there. But the disappointment was forgotten in the news which followed it. At the moment when the English troops fell back from Burgos began the retreat of the Grand Army from Moscow. Victorious in a battle at Borodino, Napoleon had entered the older capital of Russia in triumph, and waited impatiently to receive proposals of peace from the Czar, when a fire kindled by its own inhabitants reduced the city to ashes. The French army was forced to fall back amidst the horrors of a Russian winter.

Of the four hundred thousand combatants who formed the Grand Army at its first outset, only a few thousand recrossed the Niemen in December.

In spite of the gigantic efforts which Napoleon made to repair the loss of the Grand Army, the spell which he had cast over Europe was broken by the retreat from Moscow. Prussia rose against him as the Russians crossed the Niemen in the spring of 1813; and the forces which held it were at once thrown back on the Elbe. In this emergency the military genius of the French Emperor rose to its height. With a fresh army of two hundred thousand men whom he had gathered at Mainz he marched on the allied armies of Russia and Prussia in May, cleared Saxony by a victory over them at Lutzen, and threw them back on the Oder by a fresh victory at Bautzen. Disheartened by defeat, and by the neutral attitude which Austria still preserved, the two powers consented in June to an armistice, and negotiated for peace. But Austria, though unwilling to utterly ruin France to the profit of her great rival in the East, was as resolute as either of the allies to wrest from Napoleon his supremacy over Europe; and at the moment when it became clear that Napoleon was only bent on playing with her proposals, she was stirred to action by news that his army was at last driven from Spain. Wellington had left Portugal in May with an army which had now risen to ninety thousand men; and overtaking the French forces in retreat at Vitoria he inflicted on them a defeat which drove them in utter rout across the Pyrenees. Madrid was at once evacuated; and Clauzel fell back from Zaragoza into France. The victory not only freed Spain from its invaders; it restored the spirit of the Allies. The close of the armistice was followed by a union of Austria with the forces of Prussia and the Czar; and in October a final overthrow of Napoleon at Leipzig forced the French army to fall back in rout across the Rhine. The war now hurried to its close.