On the Upper Rhine, and in Alsace generally, lay Tallard with his corps. This marshal had captured certain crossing-places over the Rhine, but had all his munitions and the mass of his strength permanently on the left bank. Finally, Marcin, with his French contingent, and Max-Emanuel, the Elector of Bavaria, with the Bavarian army, held the whole of the Upper Danube, from Ulm right down to and past the Austrian frontier. Over against these forces of the French and their Bavarian allies we must set, first, the Dutch forces in the north, including the garrisons of the towns on the Meuse which Marlborough had conquered and occupied; and, in the same field, the forces in the pay of England (including the English contingents). These amounted in early 1704 to 50,000 men, which Marlborough was to command. Next, upon the Middle Rhine, and watching Tallard in Alsace, was Prince Eugene, who had been summoned from Hungary by the Imperial government to defend this bulwark of Germany, but his army was small compared to the forces in the north. Finally, the Margrave of Baden, Louis, with another separate army, was free to act at will in Upper Germany, to occupy posts in the Black Forest, or to retire eastward into the heart of Germany or towards the Danube as circumstances might dictate. This force was also small. It was supplemented by local militia raised to defend particular passes in the Black Forest, and these, again, were supported by the armed peasantry. It is essential to a comprehension of the whole scheme to understand that _before_ the march to the Danube the whole weight of the alliance against the French lay in the north, upon the frontier of Holland, the valley of the Meuse, and the Lower Rhine. The successes of Bavaria in the previous year had given the Bavarian army, with its French contingent, a firm grip upon the Upper Danube, and the possibility of marching upon Vienna itself when the campaign of 1704 should open. The great march upon the Danube which Eugene had conceived, and which Marlborough was to execute so triumphantly, was a plan to withdraw the weight of the allied forces suddenly from the north to the south; to transfer the main weapon acting against France from the Netherlands to Bavaria itself; to do this so rapidly and with so little leakage of information to the enemy as would prevent his heading off the advance by a parallel and faster movement upon his part, or his strengthening his forces upon the Danube before Marlborough's should reach that river. * * * * * Such was the scheme of the march to the Danube which we are now about to follow; but before undertaking a description of the great and successful enterprise, the reader must permit me a word of distinction between a strategic move and that tactical accident which we call a battle. In the absence of such a distinction, the campaign of Blenheim and the battle which gives it its name would be wholly misread.