On the 3rd of April the queen prorogued Parliament till the 4th of July. The Convocation had during this time kept up its bitter controversy, and had done nothing more except thank the queen for the grant of the first-fruits and tenths, and the Commons for having espoused their cause.

Marlborough had left London for the Hague on the 15th of January whilst Parliament was sitting. He was promised fifty thousand British troops under his own immediate command, and he was planning a campaign which gave the first evidence of a real military genius being at the head of the Allied forces, since these Dutch wars began. He saw that the Elector of Bavaria, by his alliance with the French, was striking at the very heart of the Empire, and that, if permitted to continue his plans, he would soon, with his French allies, be in possession of Vienna. Nothing could be more deplorable than the condition of Austria. Besides the successes of the Elector of Bavaria, the insurgents of Hungary were triumphant, and between the two the Empire was on the verge of ruin. The Elector of Bavaria had possessed himself of all the places on the Danube as far as Passau, and should he come to act in concert with the Hungarians, Vienna would be lost. Prince Eugene put himself into communication with Marlborough, and these two great generals determined on striking a blow which should at once free Austria from its dangers. This was no other than a bold march of a powerful army to the Danube, and the destruction of the Elector of Bavaria.

This was a design so far out of the mediocre range of Dutch campaigns that it was determined not to let its real character become known till it could be instantly put in execution, certain that the States-General, terrified at so daring a scheme, would prohibit it at once. To go securely to work, therefore, by the advice of Eugene, the Emperor applied to the Queen of England to send an army to his rescue. Marlborough supported the application with all his energy, and, having procured the queen's consent, he left England on the 15th of January, was in the Hague on the 19th, and put himself into secret communication with the Grand Pensionary Heinsius. He fully approved of the scheme, and promised to give it his most strenuous support. It was thought, however, imprudent to confide the real extent of the plan to other persons, not only because it was sure to alarm the States-General, but because it had been all along observed that every proposal, as soon as it became known to the Government or heads of the army, was immediately treacherously conveyed to the French. The proposal made to the States-General, therefore, was merely that the next campaign should be made on the Moselle, as if the design were to penetrate into France along that river.

The States-General, as was expected, appeared thunderstruck by even the proposal of carrying the war to the Moselle, and it was only by the zeal of Heinsius that they were brought to consent to it. That accomplished, they were induced to grant a subsidy to the Prince of Baden, and another to the Circle of Suabia, and to take into pay four thousand Würtembergers instead of the same number of Dutch and English despatched to Portugal. There was a promise of money given to the Prince of Savoy, with an assurance of so vigorous a campaign on this side of the Alps that the French should not be able to send many troops against him. Similar assurances of co-operation were given to the Elector Palatine and to the new King of Prussia. These matters being arranged, Marlborough hastened back to England, and persuaded the queen to remit a hundred thousand crowns to Suabia, and to make a large remittance to the Prince of Baden out of the privy purse. He then put himself on a good understanding with the now partly Whig Ministry, himself as well as his indefatigable duchess coming out in Whig colours. He then returned to the Netherlands in the beginning of April. He found in his absence that the terms of his design, little of it as was known, had been actively operating in the cautious Dutch mind, and the States of Zealand and Friesland in particular were vehemently opposed to so bold a measure as carrying the war to the Moselle. Marlborough, who had brought with him to support him in command his brother General Churchill, Lieutenant-General Lumley, the Earl of Orkney, and other officers of distinction, told the States plainly that he had the authority of his queen for taking such measures as he thought best for the common cause, and that he was determined to march with his forty thousand men to the Moselle. This struck with silence the opposers of the measure: the States consented with a good grace to the proposition, and gave him such powers as they never would have done had they any idea to what an extent he meant to use them. Prince Eugene alone, who was commanding the Allied army on the Upper Danube, was in the secret. Leaving Overkirk with a strong force to guard the frontiers of Holland, he commenced at once his march to Utrecht, where he spent a few days with Albemarle, thence to Ruremond, and so to Maestricht, and on the 8th of May advanced to Bedburg, in the Duchy of Juliers, which had been appointed as the place of rendezvous. There he found General Churchill with fifty-one battalions, and ninety-two squadrons of horse.

Being joined by various detachments of Prussians, Hessians, Lüneburgers, and others, and also by eleven Dutch battalions, Marlborough, on the 19th of May, commenced his great expedition into the heart of Germany. On the 26th he was at Coblentz, and from the grand old fortress of Ehrenbreitstein he watched the passage of his army over the Moselle and the Rhine. He wrote to the States-General for fresh reinforcements in order to secure his most important movement, and marched along the banks of the Rhine to Broubach. There he also wrote to the King of Prussia, praising the Prussian troops, and entreating him to send him more of them. While he was at Mainz, he halted a day to rest his troops, and there received the agreeable news that the States were sending after him twenty squadrons, and eight battalions of Danish auxiliaries; but at the same time he was mortified to find that the Prince of Baden had managed so badly as to allow the ten thousand troops forwarded by Tallard to join the Elector of Bavaria without molestation, and had lost the most tempting opportunities, whilst the Elector was marching through narrow defiles, of cutting off his march and reducing him to extremities.

The French were filled with wonder at this march of Marlborough, far out from the usual scene of the English operations, and could not for some time realise the object of it. At one time they expected only an attack on the Moselle, but that river and the Rhine being crossed, they apprehended that his design was to raise the siege of Landau, and this was confirmed by the advance of the Landgrave of Hesse to Mannheim. But when he crossed the Neckar and advanced on Erpingen, and was continually strengthened by fresh junctions of Prussians, Hessians, and Palatines, they began to comprehend his real object. He waited at Erpingen for the coming up of General Churchill with the artillery and part of the infantry, and he employed the time in sending a despatch to warn the Prince of Baden that Tallard and Villeroi were about to unite their armies, pass the Rhine, and hasten to the support of the Elector of Bavaria. He pressed on the prince the extreme importance of preventing this passage of the French army. He told him that they must not trouble themselves about any damage that Villeroi might do on the left bank of the Rhine, if he could only be kept there, as in that case he felt assured that six weeks would see the army of the Elector of Bavaria annihilated, and the Empire saved.

Marlborough was anxious to keep the Prince of Baden engaged on the Rhine, so that he might himself have the co-operation of the far abler Eugene on the Danube. On the 9th of June he crossed the Neckar again, marched to Mondelsheim, and on the 10th met for the first time Prince Eugene, who was destined to be for ever connected with his name in military glory. At Hippach Marlborough reviewed his cavalry in the presence of Eugene, who expressed his utmost admiration at their appearance and discipline. He was equally struck with the lively and ardent expression of the countenances of the English soldiers, which Marlborough handsomely assured him was caused by their pleasure in seeing so renowned a commander. To the intense mortification of Eugene and Marlborough, the Prince of Baden, whom they were anxious to detain on the Rhine, quitted the post where his presence was so much required, and came up and joined them. He was determined to be in the quarter where the greatest share of reputation was to be won, and from his princely rank he did not hesitate to claim the chief command.

This notion of their princely claims, combined with their mediocrity of military talent, has always been the mischief of a campaign in alliance with the small princes of Germany. The whole plan of Marlborough and Eugene was in danger of defeat, and Eugene was compelled to go to the Rhine, and Marlborough to admit of the Prince of Baden taking the command on alternate days. He secretly resolved, however, that any actions of consequence should be entered upon only on his own day. Eugene had now taken his departure, and on the 15th of June was at Philippsburg, on the Rhine, and Marlborough felt it time to press on, for the States-General were now continually sending to him alarming accounts of the French, and entreating him to send back part of his army for their defence. Accordingly, on the 20th, he set forward, and passed successfully the narrow, dangerous, and troublesome pass of Geislingen, lying amongst the mountains which separated him from the plains of the Danube. This pass was two miles long, heavy with the deepest mud, and abounding with torrents swollen by the rains. Once through, he came into contact with the forces of the Prince of Baden, which were posted at Wertersteppen. On the 24th the united armies reached Elchingen, near the Danube. The Elector of Bavaria, who was posted at Ulm, retired, at his approach, along the banks of the Danube to a former encampment of himself and his French allies, in a low and swampy place between Lauingen and Dillingen. Marlborough advanced to the little river Brenz, and encamped within two leagues of the enemy, with his right at Amerdighem and his left at Onderingen. There he waited till the 27th, when his brother, General Churchill, came up with the artillery and part of the infantry. The army now amounted to ninety-six battalions, two hundred and two squadrons, with forty-eight pieces of artillery, pontoons, etc. He still, however, judged it prudent to wait for the Danish horse under the Duke of Würtemberg, which were daily expected.

During this delay the Elector forestalled the Allies in securing the fortress of the Schellenberg, situated on a lofty hill overhanging the town of Donauwörth. Marlborough saw the immense advantage thus gained, and determined, cost what it might, to drive them from this stronghold. It was held by the General Count D'Arco, with twelve thousand men; and it was clear that it could not be forced without great loss. But there was no time to delay. So long as the Elector held Schellenberg he kept them in check, and was enabled to wait for the arrival of French forces sent to relieve him. The Prince of Baden was confounded at the daring of such an undertaking, and strongly opposed it; but Marlborough told him that every day's delay only enabled the enemy to strengthen himself by fresh entrenchments both there and in their swampy camp. On the 1st of July Marlborough, having the command for the day, ordered the assault of the Schellenberg. At three o'clock in the morning this hardy attempt began. The picked troops advanced to the front of the Schellenberg, crossing, on bridges prepared for the occasion, the deep and rapid stream called the Wernitz, about noon. The Austrian grenadiers were far in the rear, and it was five in the afternoon before the order was given for the column to ascend. It was a murderous prospect for the assailants. The hill was steep and rugged; the ascent was rendered additionally difficult by a wood, a rivulet, and a deep ravine; whilst the summit of the hill was covered with soldiers ready to pour down the most destructive storm of shot, and that with the prospect of an unlimited supply of soldiers and ammunition from Donauwörth and the camp on the other side of the Danube, which was connected with this side by a bridge. Lord Mordaunt with fifty English grenadiers led the way as a forlorn hope. The officers of the attacking column were nearly all killed, and it appeared likely to be swept down the hill, but a battalion of English Guards stood its ground firmly, and restored the courage of the rest, and once more they advanced. D'Arco then gathered in his flanks and threw the whole weight of his soldiery upon them to annihilate them, still pouring murderous discharges of grape into them. It appeared impossible that any body of men could exist under such disadvantages, and the whole column seemed giving way, when General Lumley rushed forward at the head of a body of horse, rallied the failing ranks, and led them again to the charge. During this terrible conflict the assailants had not been sacrificed unavenged. They had exterminated their enemies almost as fast as they came, and at this moment a powder magazine exploding in the camp of the Bavarians, spread such consternation that the Allies, taking advantage of the panic, rushed forward, burst into the entrenchments, and threw the whole force into confusion. This confusion was put to the climax by the Bavarians observing the Prince of Baden ascending the hill from the side of Donauwörth, at the head of the Imperial troops. The panic was complete; the French and Bavarians broke in every direction, and made the best of their way down the hill to secure the passage of the bridge over the Danube. The Allies gave chase, and made a fearful carnage amongst the fugitives. By the time they reached the bridge, such was the rush and crush to cross it that it gave way. Numbers were plunged into the stream and perished; numbers were driven by the force behind over the banks; numbers were massacred on the spot. Of the twelve thousand troops who had ascended the Schellenberg, only three thousand ever rejoined the Elector of Bavaria, but many came in as stragglers and joined the Allies. There were seven or eight thousand destroyed on that bloody evening.

What was to be expected from the particular spirit which the Prince of Baden had shown, took place. Though he deprecated the attack of the Schellenberg at all, and though he allowed the English to bear the terrible brunt of the ascent, and came up in the rear of the engagement, because he reached the entrenchments before Marlborough himself came up, he claimed the honour of the victory. Had he headed the attacking column, he would have had no other claim but that of a brave officer, for the whole plan of the campaign and the whole plan of the attack of the Schellenberg were Marlborough's. Had the prince had his way, there would have been no battle at all. Marlborough repelled the mean attempt to steal his victory with contempt, and spoke some homely truths to the Prince. It served the Louvestein faction in the Netherlands, however, with a pretext to injure Marlborough, by casting a medal bearing the portrait of the Prince, and on the reverse the lines of Schellenberg. But all over the world, not excepting Germany, justice was done to Marlborough, and from that moment his name became famous, celebrated in songs even by the French, dreaded by French children, whose mothers stilled them with the terrible word "Malbrouk."