After the loss of Donauwörth the Gallo-Bavarians fell back upon Augsburg, where they encamped under the guns of the fortress. Marlborough was not strong enough to attack them, and had to content himself with blockading the town while he opened communications with the Elector of Bavaria, to whom he offered tempting terms to abandon Louis and place his excellent troops once more at the disposal of the Allies. The Elector spun out the negotiations until he knew definitely that Marshal de Tallard was coming from the Rhine to his help; then he broke them off suddenly, sending word that he would sooner serve as a private soldier under the King of France than as a general in the Emperor of Austria’s army. As Marlborough now learned from Prince Eugene of Savoy, who commanded a detached force on the Danube, that the French were manœuvring to cut off the allied army from its base of supplies, he at once turned northward, and recrossing the Danube joined hands with Eugene near Donauwörth. The situation had become very serious, for though the immediate pressure on the Emperor of Austria was removed, and the French had made no attempt to invade his territories from Italy, it was essential to bring the Gallo-Bavarians to battle and defeat them before further reinforcements had increased their strength, already greater than that of the Allies. It was with much relief, therefore, that on the morning of the 12th of August Marlborough discovered that the French and Bavarians had moved down the left, or northern bank of the Danube, and were then encamped near the village of Hochstädt, a few miles up stream from his own camping-ground.[35] Their right flank was protected by the Danube, here an unfordable river, and by the village of Blenheim, standing two hundred yards from the water’s edge. The left rested on Lutzingen, a hamlet at the foot of a chain of broken and thickly wooded hills, which guaranteed it against a turning movement. Between these villages stretched a plateau, white with long lines of tents; and along the whole of its eastern front ran the shallow valley of a tributary of the Danube--the Nebel, a formidable obstacle, for though the stream in itself was insignificant the bogs and marshes through which it flowed were very difficult to cross, and the side of the valley rose so gently towards the camp that it formed a natural glacis, well suited to the movements of all arms. Between Blenheim and Lutzingen were two other villages--Unterglau, on the eastern or far side of the Nebel, was occupied as an advanced post; Oberglau, on the western or near side, was part of the main line of defence. To hold this very strong position, about four miles in length, de Tallard who commanded the Gallo-Bavarians could dispose of an army from 56,000 to 60,000 strong, and sixty guns.