At Stillwater, information was obtained that Burgoyne had evacuated Castletown; so that the only communication with Ticonderoga, whence nearly all his supplies were drawn, was through Lake George; and that the garrison of that important place had been reduced to three hundred men. In consequence of this intelligence, the orders to General Lincoln were countermanded, and he was directed with the militia of Massachusetts, New Hampshire, and of the Grants, making, as was understood, a total of between two and three thousand men, to place himself in the rear of the British army, and cut off its communication with the lakes. Here too he was informed that Colonel St. Leger, with a large body of Indians, in addition to his regulars, had penetrated from Oswego, by the way of the Oneida lake and Wood creek, to the Mohawk, where he had laid siege to fort Schuyler, and had totally defeated General Herkimer, who had raised the militia of Tryon county, in order to relieve the fort. The importance of protecting the inhabitants from the savages, and of preventing a junction between St. Leger and Burgoyne, and the consequent loss of the country on the Mohawk, determined Schuyler, weak as he was, to detach Major General Arnold with three continental regiments to raise the siege. The army was so enfeebled by this measure, that its removal to a place of greater security became necessary, and it was withdrawn to some islands in the confluence of the Hudson and the Mohawk, where the camp was deemed more defensible. Burgoyne had now marched down the east side of the Hudson, and his advanced parties had crossed the river, and occupied the ground at Saratoga. [Sidenote: St. Leger invests Fort Schuyler.] On the 3d of August, after a message vaunting of his strength, and demanding a surrender, which was answered by a declaration that the fort would be defended to the last extremity, St. Leger invested fort Schuyler. The garrison amounted to six hundred men, all continental troops, who were commanded by Colonel Gansevoort. The besieging army rather exceeded fifteen hundred, of whom from six to nine hundred were Indians. On the approach of the enemy, General Herkimer, who commanded the militia of Tryon county, assembled them in considerable numbers, and gave information to the garrison, about eleven in the morning of the sixth, of his intention to force a passage that day through the besieging army. Gansevoort determined to favour the execution of this design by a vigorous sortie; and upwards of two hundred men, to be commanded by Lieutenant Colonel Willet, were drawn out for that purpose. [Sidenote: Herkimer, advancing to the relief of the fort, falls into an ambuscade, and is defeated with loss.]