He met with a splendid response from all classes, and a fine army of 90,000 men was equipped and placed in the field under the command of Marshal Villars. The long delay over the negotiations prevented Marlborough and Eugene from taking the field until June. They found Villars had meanwhile entrenched himself in Artois in a very strong position. Marlborough's proposal to advance by the sea-coast and outflank the enemy being opposed both by Eugene and the Dutch deputies as too daring, siege was laid to Tournay. Campaigns in those days were dilatory affairs. Tournay was not captured until September 3; and the allies, having overcome this obstacle without any active interference, moved forward to besiege Mons. They found Villars posted at Malplaquet on a narrow front, skilfully fortified and protected on both flanks by woods. A terrible struggle ensued (September 11, 1709), the bloodiest in the war. The Dutch troops gallantly led by the Prince of Orange attacked the French right, but were repulsed with very heavy losses. For some time the fight on the left and centre of the French line was undecided, the attacking columns being driven back many times, but at length the allies succeeded in turning the extreme left and also after fearful slaughter in piercing the centre; and the French were compelled to retreat. They had lost 12,000 men, but 23,000 of the allies had fallen; the Dutch divisions had suffered the most severely, losing almost half their strength. The immediate result of this hard-won victory was the taking of Mons, October 9. The lateness of the season prevented any further operations. Nothing decisive had been achieved, for on all the other fields of action, on the Rhine, on the Piedmont frontier and in Spain, the advantage had on the whole been with the French and Spaniards. Negotiations proceeded during the winter (1709-10), Dutch and French representatives meeting both at the Hague and at Geertruidenberg. The States were anxious for peace and Louis was willing to make the concessions required of him, but Philip V refused to relinquish a crown which he held by the practically unanimous approval of the Spanish people. The emperor on the other hand was obstinate in claiming the undivided Spanish inheritance for the Archduke Charles. The maritime powers, however, would not support him in this claim; and the maritime powers meant England, for Holland followed her lead, being perfectly satisfied with the conditions of the First Barrier Treaty, which had been drawn up and agreed upon between the States-General and the English government on October 29, 1709. By this secret treaty the Dutch obtained the right to hold and to garrison a number of towns along the French frontier, the possession of which would render them the real masters of Belgium. Indeed it was manifest that, although the Dutch did not dispute the sovereign rights of the Archduke Charles, they intended to make the southern Netherlands an economic dependency of the Republic, which provided for its defence.
The negotiations at Geertruidenberg dragged on until July, 1710, and were finally broken off owing to the insistence of the Dutch envoys, Buys and Van Dussen, upon conditions which, even in her exhausted state, France was too proud to concede. Meanwhile Marlborough and Eugene, unable to tempt Villars to risk a battle, contented themselves with a succession of sieges. Douay, Bethune, St Venant and Aine fell, one after the other, the French army keeping watch behind its strongly fortified lines. This was a very meagre result, but Marlborough now felt his position to be so insecure that he dared not take any risks. His wife, so long omnipotent at court, had been supplanted in the queen's favour; Godolphin and the Whig party had been swept from power; and a Tory ministry bent upon peace had taken their place. Marlborough knew that his period of dictatorship was at an end, and he would have resigned his command but for the pressing instances of Eugene, Heinsius and other leaders of the allies.
The desire of the Tory ministry to bring the long drawn-out hostilities to an end was accentuated by the death, on April 17, 1711, of the Emperor Joseph, an event which left his brother Charles heir to all the possessions of the Austrian Habsburgs. The Grand Alliance had been formed and the war waged to maintain the balance of power in Europe. But such a result would not be achieved by a revival of the empire of Charles V in the person of the man who had now become the head of the House of Austria. Even had the Whigs remained in office, they could hardly have continued to give active support to the cause of the Habsburg claimant in Spain.
One of the consequences of the death of Joseph I, then, was to render the Tory minister, Henry St John, more anxious to enter into negotiations for peace; another was the paralysing of active operations in the field. Eugene had been summoned to Germany to watch over the meeting of the Imperial Diet at Frankfort, and Marlborough was left with an army considerably inferior in numbers to that of his opponent Villars. Thus the only fruit of the campaign was the capture of Bouchain. Meanwhile the French minister Torcy entered into secret communications with St John, intimating that France was ready to negotiate directly with England, but at first without the cognisance of the States. The English ministry on their part, under the influence of St John, showed themselves to be ready to throw over their allies, to abandon the Habsburg cause in Spain, and to come to an agreement with France on terms advantageous to England. For French diplomacy, always alert and skilful, these proceedings were quite legitimate; but it was scarcely honourable for the English government, while the Grand Alliance was still in existence, to carry on these negotiations in profound secrecy.