England thus entered on the war of the Spanish Succession as the ally of continental powers banded together against France, and hampered by having to act in concert with them, as well as supported by their strength. In the patient tact requisite for managing a body of allies with diverging interests, and practically no bond of union except hostility to the enemy, Marlborough was perhaps never excelled. In military skill he was vastly William's superior, being on the whole the first of an age fertile in good generals. The weak point in his position was that it depended on the personal favour of a stupid woman: when his wife lost her influence over queen Anne, his political antagonists in England found no great difficulty in bringing about his disgrace. Marlborough was not a good man; he was greedy of money and of power, and unscrupulous as to the means he adopted for gaining them. As a general however he had the virtues never too common, and almost unknown in his age, of humanity towards the peaceful population even of a hostile country, and of attention to the welfare of his own soldiers. Like Wellington a century later, he was habitually careful of the lives of his men, though he knew how to expend them when the occasion demanded it. Like Wellington also he never lost his patience and coolness of judgment, either in the excitement of battle or in dealing with troublesome allies. In fact the two great Englishmen were conspicuously alike, at least in their military character, though there is no real doubt that Marlborough had the greater genius.
The commencement of the war was uneventful. The king of France had taken possession of Belgium in the name of his grandson Philip, the French claimant of the crown of Spain, which alarmed the Dutch for their homes. In Spain itself the French party was preponderant, but not unopposed. Louis had every motive for standing on the defensive. Marlborough was as yet powerless to move his allies. It was not until the alliance of Bavaria with France opened a road for French armies into the heart of Germany that decisive events occurred. The chief item in the French plans for 1704 was that Marshal Tallard should march from the Rhine into Bavaria, where another army under Marsin had wintered; then the two armies, combined with the Bavarian contingent, were to advance down the basin of the Danube. It was calculated that the Emperor, already greatly hampered by an insurrection in Hungary, would be unable to oppose effectual resistance, and would purchase peace on almost any terms. If this were achieved, the keystone of the alliance against France, the candidature of an Austrian prince in Spain, would be removed, and the whole fabric might be expected to collapse. The plan was well conceived: it was an instance, on the great political scale, of acting upon the fundamental military maxim—strike at the vital point. But for Marlborough it must have succeeded, so far as anything can be safely predicted in war. But for the practice, invariable in that age and perhaps inevitable by reason of the badness of roads and of organised supply, that all military operations should be suspended during the winter half of the year, Marlborough would have had no time to prepare his counter stroke. His plan was indeed fully thought out before the winter, in concert with the imperial general Eugene of Savoy, but he had many obstacles to overcome before it could be carried into operation. Even to the English cabinet he did not venture to disclose his whole purpose, but he succeeded in obtaining a large addition to his own army, and increased money grants. The Dutch had but one idea, to guard their own frontier: they would not even assent beforehand to Marlborough's proposal, intended to conceal his real object from friend and foe alike, that he with part of the German contingents should operate against France from the Moselle, while the Dutch, with the rest of the Germans, defended the Netherlands. Marlborough was obliged to be content with the assurance of his one firm supporter in Holland, the Pensionary Heinsius, that consent should be obtained when the time came. Much trouble had also to be taken with other minor members of the confederacy, but Marlborough attained his ostensible object of being free to move with his own army to the Moselle.
Not until Marlborough with his army had reached Coblenz, did he give any hint of his intentions, except to the two or three persons necessarily in his confidence. Even then he only declared to the Dutch that he found it necessary to go further south; and they, finding that a deaf ear was turned to their remonstrances, let Marlborough take his own course, and even sent reinforcements after him. The distance to be traversed, the necessity of arranging every detail for troops moving by different routes, made his progress necessarily slow. The French did not in the least guess his design, but nevertheless persevered in their plan of reinforcing the army in Bavaria, a process which the Margrave of Baden, who commanded for the allies on the upper Rhine, ought to have rendered much more difficult. Not till Marlborough, ascending the Neckar, began to penetrate the hill country that separates the basins of the Neckar and Danube, was his real purpose apparent. He had before then met Eugene of Savoy, who was as he hoped to command the imperial army destined to co-operate with him: but the Margrave of Baden, who was Eugene's senior in rank, insisted on taking the more important part, and leaving Eugene to command on the Rhine. Marlborough's purpose was something like Napoleon's at the beginning of the famous Austerlitz campaign, to concentrate his army, reaching the Danube by various routes, near Ulm. In Marlborough's time however Ulm was not yet an important fortress: and the Elector abandoned it on the allies appearing in the vicinity, and marched down the Danube to a great intrenched camp near Dillingen. Marlborough's first object was necessarily to secure a point of passage across the Danube: and he determined to seize Donauwerth, a small fortified town lower down. His zeal was quickened by the tidings that the French army under Marshal Tallard was on the point of marching from Strasburg to assist the Elector. He therefore, as soon as his troops had come up in sufficient numbers, without waiting for full concentration, circled round Dillingen, and directed his march on Donauwerth. The Elector divined his intention, and occupying that town, with the hill of the Schellenberg adjoining it, began to put in order the fortifications. Marlborough saw the urgent necessity for haste: a couple of days' delay might render the works on the Schellenberg unassailable, in which case his chance of securing a bridge over the Danube before Tallard arrived would be but small. He therefore ordered an attack immediately on reaching the place, though his men had had a very long march, and it was verging towards evening.[56]
Donauwerth stands on the north bank of the Danube, just below the junction of a tributary, the Wernitz. The Schellenberg, a large flat-topped hill, immediately adjoins the town on the east. A continuous line of works existed, passing along the brow of the hill, and extending to the fortifications of Donauwerth on one side and down to the Danube on the other; only the central portion however was in a state fit for defence, though the enemy was at work on the remainder. Marlborough arrived in person with his cavalry before Donauwerth on the forenoon of July 2. While waiting for the infantry to come up, he caused bridges to be thrown over the Wernitz, and ordered a site for a camp to be marked out, thus giving the enemy the impression that no attack was intended, at any rate until next day. At 6 p.m. however the pick of Marlborough's army assailed the hill: after a long and desperate struggle, in which the allies lost heavily, the enemy were routed, and fled down the reverse slope to the Danube. The crush broke down the bridge, and thousands were precipitated into the rapid stream. Scarcely more than a quarter of the defenders of the Schellenberg reached the Elector's camp. As a consequence of this defeat the Elector abandoned Donauwerth, as well as Dillingen, and retired to Augsburg, where he shut himself up, while Marlborough ravaged Bavaria, in the vain hope of compelling the Elector to abandon the French alliance. Nuremberg became the centre of Marlborough's supply system, which was elaborated in a manner far in advance of his age; and the devastation[57] of Bavaria made him even more dependent on his magazines than he would otherwise have been. As Tallard was now approaching from the Rhine, with a force that Eugene was powerless to stop, the allies found it necessary to abandon the southern bank of the Danube. Marlborough and Eugene persuaded the Margrave of Baden that to capture Ingolstadt, a fortified town lower down the river, would be a higher distinction than to await attack from the French. They themselves united their armies at Donauwerth on the northern bank, and marched up the river towards the enemy, whom they found encamped beyond the Nebel, a small tributary of the Danube.
The line occupied by the French and Bavarians ran nearly north and south, and extended for about four miles. They had naturally formed their camp on the higher ground west of the Nebel, the course of which was marshy along the whole front, troublesome to cross everywhere, and believed by the French to be a much greater obstacle than it really was. Tallard, misconstruing information that he had received, was under the impression that Eugene's army had not joined Marlborough, and that therefore the movement before dawn on August 13, of which he was apprised, was a retreat northwards. The body of cavalry which escorted the allied generals to the Nebel, when they rode in advance of their armies to reconnoitre, was supposed to be detached to cover this retreat. Nothing was further from the minds of the French generals than the expectation of being attacked where they were. Hence they had taken no steps, as they might easily have done, to render their front virtually unassailable. Hence also, when the morning fog cleared off, and discovered columns of infantry at the edge of the higher ground which bordered the valley of the Nebel on the east, they were in too great a hurry to do anything but form line of battle on the ground which they already occupied.
The Nebel emerges from the wooded uneven country to the northwards about a mile east of Luzingen, in which village were the Elector's head-quarters. A little lower down, also on the right bank of the stream, is the village of Oberglauheim. The infantry of the joint army, commanded by the Elector and Marshal Marsin, was drawn up from Luzingen to Oberglauheim, most of its cavalry on the right, extending further to the south. Marshal Tallard's infantry was most of it posted in Blenheim,[58] a village close to the Danube; his cavalry continued the line to the north till they met Marsin's, but had a reserve of infantry behind its centre. The artillery, which was not numerous in proportion, was distributed at intervals. The French apparently believed the Nebel to be impassable from Oberglauheim to Blenheim, where there were some mills on the stream, which however they neglected to occupy: nor had they effectually broken the bridge by which the high-road crosses the Nebel. About Unterglauheim, a hamlet on the left bank half-way between the two, there lies a wide piece of swamp. During a great part of the year, or after heavy rain, the Nebel might no doubt be a very serious obstacle, but in August the difficulty could be overcome. Their want of care to ascertain the truth on this point was the direct cause of their defeat. Their dispositions had two ruinous defects, the Nebel being passable: first, their line was fatally weak in the centre, where for a long distance it consisted almost entirely of cavalry: secondly, they were posted so far back from the stream that there was room for the enemy to form line for attack after struggling through it. The latter error might easily have been remedied by a short advance, but nothing was done. Tallard, it is said, uneasy about the weakness of the centre when he saw the enemy massing at Unterglauheim, urged Marsin to post his reserve of infantry there; but Marsin thought, rightly as the event showed, that his reserves were needed on the left. Why Marshal Tallard did not withdraw from Blenheim several of the useless thousands that crowded it, is a question easier to ask than to answer.
Tallard had plenty of time to correct his dispositions, had he known how, for the battle did not begin for several hours after the allies came in sight. Eugene and Marlborough had agreed that the army of the former should constitute the right, Marlborough's the left, of the line of battle. As their line of march had been near the Danube, and the ground through which Eugene's columns had to make their way was broken and wooded, it was a long time before he was opposite Luzingen, ready to begin the action, and Marlborough was of course obliged to wait for him. The allied generals had discerned the defect in the French position: a vigorous attack on the centre ought to cut the line in half. Their plan was that Eugene should occupy the Elector and Marsin, and that Cutts with Marlborough's left should assail Blenheim directly, while the duke himself undertook the decisive movement. All preparations were duly made while Eugene was on the march: the pontoon train was brought up, and bridges laid at intervals from Unterglauheim downwards: the artillery was posted to command the opposite bank: troops were pushed forward to seize the small existing bridges near Blenheim. Except for a not very serious cannonade, Tallard remained inactive: he had in fact no longer any choice, unless he retreated (for which there was no reason), after he had allowed all the passages of the Nebel to fall into his enemy's hands. About one o'clock came the welcome news that Eugene had completed his march, and the battle began at once on both flanks. Of the conflict on the right very little need be said. The Nebel above Oberglauheim was not a real obstacle, and Eugene attacked directly. The contest was long and obstinate, with considerable vicissitudes: Eugene's troops, exhausted by the long march under a hot sun, were scarcely equal to the exertion required of them. The Elector and Marsin held their ground till Tallard was routed, and then made an orderly retreat, but they could not spare a man to help their colleague. Eugene's share in the action, though not in itself successful, was a necessary and important contribution to the victory.