The affairs of the Grand Alliance failed to prosper elsewhere as Philip V proved to be popular in much of Spain, and Maximilien-Emmanuel Wittelsbach the Elector of Bavaria, having combined forces with the French, moved on to threaten Vienna. If this threat became reality, and Vienna should be occupied, even for a short time, then the Grand Alliance would almost certainly fall apart.
Early in 1704, Queen Anne gave her consent to a plan hatched by Marlborough and the Austrian ambassador, Count Wratislaw, to go to the aid of the emperor. In effect, Marlborough would take those troops in the queen’s pay up the course of the river Rhine to combine with the Imperial troops in southern Germany and confront the elector to remove the threat to Vienna. For Marlborough, this offered the chance to be free of the constraints imposed on him by the Dutch, while countering one of Louis XIV’s main strategic initiatives, that of driving Austria out of the war. The southern frontier of Holland would be exposed by such a movement, but the Dutch troops in Marlborough’s army would remain on guard there, under the reliable command of Veldt-Marshal Overkirk. The duke could see, and managed to persuade his Dutch colleagues of the fact, that if he marched south, the French would be unable to ignore the strategic re-balancing that was being made in the Allies’ war effort and would have to follow, so that the immediate threat to Holland would subside.
Speed was of the essence in order that the French should remain off-balance. The remarkable march of Marlborough’s army in the early summer of 1704, from the Low Counties up the course of the Rhine and then across the passes of the Swabian Jura mountains, is well known, a major switch in the emphasis of the efforts of the Grand Alliance from northern to southern Europe. The dramatic change went virtually unchallenged while it was in progress; Louis XIV was taken by surprise at such an audacious move, and his army in Bavaria, under the command of the recently promoted Marshal Ferdinand Marsin was soon under threat. The countermove by the king was to hurriedly send a fresh French army, commanded by Marshal Tallard, through the Black Forest passes to go to the support of Marsin and the Elector of Bavaria. In the meantime, dictating the pace of the campaign and always one step ahead, Marlborough had joined Prince Eugene of Savoy, the president of the Imperial War Council, and the Margrave of Baden, the Imperial field commander, and agreed with them a joint strategy to deal with the threat to Vienna. In short, Eugene would go to hold the upper Rhine secure, while Marlborough and Baden combined forces to engage Marsin and the elector on the Danube.
First of all, Marlborough had to get his army across the river Danube and interpose it between Vienna and the French and Bavarian forces. This he did in emphatic style on 2 July 1704, by seizing the partly fortified Schellenberg hill above the small town of Donauwörth at the junction of the Wornitz River with the Danube, and he destroyed Count d’Arco’s Franco-Bavarian force there in the process. Marlborough now had a secure crossing to the southern bank of the Danube. Having placed his army between Vienna and the French and Bavarians, his principal objective in the campaign, he could operate almost at will in the region. On the other hand, of course, Marsin and the elector might come out of their defences to fight, although news of the approach of a fresh French army under Tallard was soon received in the Allied camp, and it seemed almost certain that nothing would be attempted until Tallard’s arrival in Bavaria. Meanwhile, in an effort to prise the elector away from the French, the duke embarked on a ruthless campaign of destruction in Bavaria, but the elector was not to be moved from his own set course and clung to his alliance with Louis XIV, despite the urging of his wife. By late summer there was something of a stalemate in southern Germany; Marlborough could not winter his army south of the Danube, at least partly because the region had been devastated by his own cavalry and dragoons. The alternative was to withdraw along his own newly established supply lines towards Nuremburg in central Germany, but this would be a tacit admission of failure, and whether the campaign in the south could be renewed in 1705, with the Dutch growing more anxious at the duke’s continued absence, was very much in doubt. Also in doubt would be Marlborough’s reputation as a commanding general who could deliver real success, particularly as many politicians in London were far from convinced that their troops should be so far away at all, on what might prove to be a fool’s errand.
On 13 August 1704 all such misgivings were set to rest. Marlborough had joined forces with Prince Eugene and attacked and defeated the French and Bavarian armies on the plain of Höchstädt, in the battle that became known as Blenheim (from the nearby village of Blindheim, into which Marshal Tallard’s French infantry were pointlessly packed and then herded away as prisoners of war). ‘We took them all prisoners,’ Donald McBane, serving with Orkney’s Regiment, wrote, ‘they laid down their arms and marched a mile to the right of our army, we took a great many of their head officers, with the standards, tents, and their whole Train and ammunition.’ In the aftermath of utter defeat, Marshal Marsin and the elector conducted a withdrawal to the Rhine with their own battered forces, and the closing months of the year saw a series of hard-fought rearguard actions and sieges of such places as Landau in Alsace and Trarbach on the Moselle. This dogged resistance, conducted in part by François de Neufville, Marshal Villeroi, a close friend of Louis XIV, slowed the Allied progress and prevented Marlborough from making the most of his astonishingly successful campaign that summer. Despite this, the French king had lost the ability to win the war on that terrible day in August; the complete destruction of one of his main field armies was a blow that could not easily be set right. ‘The loss of France could not be measured by men or fortresses. A hundred victories since Rocroi had taught the world to regard the French army as invincible, when Blenheim, and the surrender of the flower of French soldiery, broke the spell.’ All this might be so, but Louis XIV had not yet lost the war – it remained to be seen whether the Grand Alliance could make the most of this turn of events and prudently achieve an advantageous peace for themselves.
The victory at Blenheim, so unexpected and so complete, was greeted with relief and jubilation across the Alliance. Marlborough was the hero of the hour, seen to be clearly one of the great captains of all time, a true ‘master of the field’. Honours flowed to him and his commanders. Eugene had his share of glory, of course, although the Margrave of Baden had gone to lay siege to the Bavarian-held fortress of Ingolstadt early in August and had not, to his regret, been present on the day of victory. Making the most of this success, however, was not that simple, and the duke found that he was unavoidably drawn back into the Low Countries to campaign in 1705. His overall plan for the year, almost certainly too ambitious and optimistic, was to take his troops to combine with the Imperial army under Baden to sweep through the Moselle valley into the heart of northern France, while Veldt-Marshal Overkirk held the line with a Dutch corps in the Southern Netherlands. Nothing went well – the weather was bad, the Margrave was delayed (partly due to still convalescing from a wound to his foot suffered at the Schellenberg). The duke, Captain Robert Parker wrote, ‘was greatly chagrined at the disappointment, as he had conceived great hopes of penetrating France that way . . . had the prince [Baden] joined him according to their agreement, the French must have drawn from the Netherlands a good part of their troops.’ It would, though, not have been quite so simple as the good captain suggests, for the formidable Marshal Villars, always a sound tactician, held strong defensive positions along the line of the Moselle. In addition, Emperor Leopold had died in Vienna that May, adding uncertainty to the Alliance. To complicate all this, the contractor who was supposed to be gathering stores in Trier embezzled the funds and defected to the French instead. Marlborough’s troops were out of position and short of supplies: ‘We camped on a hill called Hungry Hill,’ Donald McBane remembered ruefully.
Matters turned worse on 10 June, when Marshal Villeroi seized the town of Huy on the Meuse River, and Overkirk, thoroughly alarmed at the sudden French move, urgently sent word for Marlborough to return as soon as he could. The duke had little option but to abandon his already faltering Moselle campaign and force march his troops back to the Low Countries, where Huy was soon recovered and Villeroi forced back behind his defences. These works, known as the Lines of Brabant, stretched in a huge arc some 60 miles long, from Antwerp in the north down to Namur on the Meuse, and shielded the French field army as it manoeuvred to counter whatever Marlborough and Overkirk might attempt. On 17 July 1705 Marlborough forced his way through the lines at Elixheim on the Gheete stream and drove off the French and Bavarian detachment he met there with heavy losses. Villeroi fell back behind the shelter of the Lys River to cover Louvain, but a move by the duke to confront him there was frustrated by Dutch reluctance to move quickly enough once an initial crossing of the river had been accomplished. A month later, in mid-August, an attempt by the duke to overwhelm a French force under the Marquis de Grimaldi on the Yssche River to the south of Brussels failed because the Dutch generals and their field deputies were unwilling to undertake what they, quite understandably in fact, foresaw would be an expensive engagement. The duke might invite his allies to come to a ball, but he could not, yet, be sure that they would dance.
For his part, Marlborough declared that he would no longer work under such restrictions. The States-General, tacitly acknowledging that the campaign had stalled at least in part due to the restrictions under which he had to operate, quietly transferred elsewhere the more obstinate and short-sighted of their generals and field deputies and assured the duke of full cooperation in future. ‘If he would continue at the head of the army on their frontier . . . they would readily comply withal.’ To a large degree, they proved to be as good as their word in the years that followed. Difficulties did persist, however, over the precise terms of service and prompt payments of subsidies with some of the Protestant leaders who provided such excellent troops for the Alliance, a number of whom, welcome and gifted with military expertise or otherwise, wished to take the field in person.