In spite of the enemy's numerical inferiority, Napoleon had been thwarted at Eylau by the weather, by the unsurpassed bravery of the Russian soldiers, and by the able tactics of Bennigsen. The latter had not been worsted in the arbitrament of arms, yet the Emperor's character for resolution and energy had virtually defeated the Russians, and had given him not only a technical but a real victory. Although he fell back and assumed the defensive, feeling that without enormous reinforcements and the capture of Dantzic he could not resume the offensive, yet nevertheless he had remained for four months unmolested by his foe. Bennigsen's perplexities were great. The Russian court was rent by dissensions, affairs at Constantinople were occupying much of the Czar's attention, and the force available for fighting in the North seemed too small for a decisive victory: he remained virtually inert. There was an effort late in February to drive the French left wing across the Vistula, but it failed. A few days later Napoleon in person made a reconnaissance on his right, and this show of activity reduced the opposing ranks to inactivity. He had proposed to resume hostilities on June tenth, and had by that time increased his strength on the front to one hundred and sixty thousand men, all well equipped and fairly well fed. The reserve army in central Europe was much larger; there were about four hundred thousand men, all told, in the field. [Illustration: Battle of Heilsberg.] Meanwhile, however, the pleasant season had mended the roads and dried the swamps. The Russians were refreshed by their long rest, and, children of nature as they were, felt the summer's warmth as a spur to activity. Bennigsen had by that time about ninety thousand men, excluding the Prussians, who now numbered eighteen thousand. By his delay he had lost the services of his best ally, the inclement weather; but he had at least come to a decision, and forestalling Napoleon's scheme, advanced on June sixth to the Passarge, against Ney's corps, which was the French advance-guard. Ney retreated, and the seventh was spent in manoeuvers which resulted in uniting his corps with the main army. Bennigsen, having hoped to cut off and destroy his division before attacking in force, felt compelled, in consequence of failure, to retreat in turn, and this movement left Lestocq at a dangerous distance to the right. At this juncture Napoleon determined to assume the offensive himself. On the eighth he began to concentrate his troops, and took measures to find the enemy in order to force a battle. Bennigsen had withdrawn beyond the river Alle; Soult and Lannes, with Murat in advance, were sent up its left bank to Heilsberg; Davout and Mortier were to pass farther on, as part of a general movement to surround; Ney and the guard were held in reserve, while Victor was despatched to block Lestocq.