It was on the 18th of May that Louis of Baden appeared at the head of his army in the Black Forest and initiated that separation of the Bavarian forces from the French which was a necessary part of the general plan we have spoken of. It was but a few hours since Tallard had stretched out his hand and passed the recruits and the provisions over to the Franco-Bavarian forces. The Elector of Bavaria had with him certain French regiments, and Marshal Marcin was under his commands, while Marlborough's plan was still quite unknown. Therefore no large French force could apparently be spared from the valley of the Rhine to help the Elector in that of the Danube; the Duke of Baden could have things his own way against the lesser force opposed to him. On the 19th he was advancing on Ober and Neder Ersasch. The Duke of Bavaria had evacuated these villages upon the 20th, and on the same night the Duke of Baden reached Meidlingen. Pursuer and pursued were marching almost parallel, separated only by the little river of Villingen. Now and then they came so close that Baden's artillery could drop a shot into the hurrying ranks of the Elector. On the 21st Baden was at Geisingen, threatening Tuttlingen. On the 23rd he had reached Stockach, and was pressing so hard that his van had actually come in contact with the rear of the Bavarians, a situation reminiscent of the Esla Bridge in Moore's retreat on Coruña. The valley of the Danube opened out before the two opponents. The Elector found it possible to maintain his exhausted but rapid retreat, and, ten days later, he had escaped. For by the 3rd of June the Franco-Bavarian forces lay at Elchingen, the Duke of Baden was no nearer than Echingen, and the former was saved after a fortnight of very anxious going; but, though saved, they were now completely cut off for the moment from French reinforcement. Marlborough was approaching the hills; he would cross them in a few days. He would join Baden's army; and the moment Marlborough should have joined Baden, the Elector would be in peril of overwhelming adversaries. We have seen how the plan matured. Three weeks after the Bavarian army's escape from the Black Forest, upon the 22nd of June, Marlborough's force had crossed the range and made one with Baden's before Ulm. PART IV THE SEVEN WEEKS--THE THREE PHASES From the day when the Duke had appeared upon the southern side of the mountains, and was debouching into the plains of the Danube, to the day when he broke the French line at Blenheim, is just over seven weeks; to be accurate, it is seven weeks and three days. It was on the last Sunday but one of the month of June that he passed the mountains; it was upon the second Wednesday of August that he won his great victory. These seven weeks divide themselves into three clear phases. The first is the march of Marlborough and Baden upon Donauwörth and the capture of that city, which was the gate of Bavaria.