By the evening of the 25th the whole French army was over the Niemen and pushing forward to Vilna. Murat opened the march with the 1st and 2nd Cavalry Corps. Behind were the 1st and 3rd Corps, the 3rd Cavalry Corps, and the Imperial Guard, while the 2nd Corps had crossed the Vilia at Kovno and was marching along its right bank, thus forming the flank-guard of the advance on Vilna, and threatening to cut off Wittgenstein towards Keidani. Davout and Ney had each detailed a foreign regiment to guard Kovno and the bridges. The 10th Corps was ordered to advance from Tilsit upon Rossieni, sweeping the right bank of the Niemen, and thus clearing the course of the river for Baste’s supply flotillas, which were now collecting at Tilsit, whence they were pushed forward to Kovno. There was practically no fighting on the march to Vilna. The thin chain of Russian cavalry posts steadily retired as the French pressed forward: only a few shots were fired from time to time. Napoleon hoped for a battle at Vilna and the troops made forced marches day after day to attain the desired end, at great cost to themselves, for the weather was sultry, the roads were bad, and the provision trains were already falling to the rear. The men began to leave the ranks in order to forage for supplies, and the horses, ill-fed and over-worked, broke down and died in great numbers. Even the artillery was ill-horsed from the first, and the officers were forced to scour the country for draft animals, often with very little success. Barclay was in position before Vilna with the 3rd Corps and most of the 4th, and Baggohufwudt was in touch to the north; but Alexander and his suite had already left for Sventsiani, and Barclay was merely waiting until the French began to close. The stores which could not be carried off were destroyed, and at 4 a.m. on the 28th the 3rd and 4th Corps began to defile through the town. Barclay and his staff left about 1 p.m.; and the rear-guard followed, burning the bridge over the Vilia. Bruyère’s cavalry division, which was heading the French advance, came through the town before Barclay’s cavalry rear-guard was quite clear of the suburbs; and its leading regiment, the 8th Hussars, was charged and driven back, with the loss of several prisoners, by the Cossacks of the Imperial Guard. The Russian columns were well on their way to Sventsiani, and after three days of forced marching in tropical weather the French impulse had expended its force.