The advice was not unwise. It did, as a fact, immobilise Eugene for the moment, and kept him upon the Rhine for some weeks, but, as we shall see later, that General was able to escape when the worst pressure was put upon him, to cross the Black Forest with excellent secrecy and speed, and to effect his junction with Marlborough in time for the battle of Blenheim. But, meanwhile, Baden had chased the Elector of Bavaria out of the Black Forest and down on to the Upper Danube. Marlborough might, at any moment, join hands with Baden. The Elector sent urgent requests for yet more reinforcements from the French, and Tallard, in a letter to Versailles of the 16th of June, advised the capture and possession of such points in the Black Forest as would give him free access across the mountains, the proper provisioning of his line of supply when he should cross them, and the accomplishment of full preparations for joining the Elector of Bavaria in a campaign upon the Upper Danube. Let the day when the French court received this letter be noted, for the coincidence is curious. At the very moment when Tallard's letter reached Versailles, the 22nd of June, Marlborough was effecting his junction with Baden outside the gates of Ulm at Ursprung. The decision of Louis XIV., that Tallard should advance beyond the hills in force to the aid of the Elector, exactly coincides with the appearance of the English General upon the Danube, and it was on the 23rd of June, the morrow, that the King wrote to Villeroy the decisive letter recommending Tallard to cross over from Alsace towards Bavaria with forty battalions and fifty squadrons, say 25,000 men. But this advance of Tallard's across the Black Forest and his final junction with the Elector and Marcin before the battle of Blenheim did not take place until after Marlborough had joined Baden and the march to the Danube was accomplished. It must therefore be dealt with in the next division, which is its proper place. For the moment we must return to Marlborough's advance upon the Danube, which we left at the point where he crossed the Neckar upon the 3rd and 4th of June. He had, as we have just seen, and by methods which we have reviewed, completely succeeded in saving the rest of his advance from interference. Safe from pursuit, and with no further need for concealing his plan, Marlborough lingered in the neighbourhood of the Neckar, partly to effect a full concentration of his forces, partly to rest his cavalry. It was a week before he found himself at Mundelsheim, between Heilbron and Stuttgart, and at the foot of the range which still divided him from the basin of the Danube. Here Eugene, the author of the whole business, met Marlborough; between them the two men drew up the plans which were to lead to so momentous a result, and knitted in that same interview a friendship based upon the mutual recognition of genius, which was to determine seven years of war.