In fact he was on the brink of a series of disasters which for him would end in ruin.
The first consequence of Charles' move fell on Lewenhaupt. On September 15, the day Charles broke camp at Tatarsk and marched south, Lewenhaupt was still thirty miles west of the Dnieper. Charles' position at that moment was sixty miles east of the river. Peter immediately saw his opportunity: The ninety-mile gap left the wagon train exposed. The Tsar dispatched his main force southward with Sheremetev to shadow Charles, but he held aside ten battalions of his best infantry, including the Preobrazhensky and the Semyonovsky Guards. Mounting these infantrymen on horseback and supplementing them with ten regiments of dragoons and cavalry, he created a new, highly mobile "flying corps" of 11,625 men of which he took personal command. With Menshikov at his side, Peter rode directly west to intercept Lewenhaupt. Although the Tsar did not know Lewenhaupt's strength, reports reaching Russian headquarters placed it at around 8,000. Actually, it as 12,500. As a precaution, Peter ordered an additional 3,000 dragoons under Bauer to ride west to join his force. Thus, 14,625 Russians were moving to intercept 12,500 Swedes.
Meanwhile, Lewenhaupt's weary column, still lumbering forward after three months on the road, finally reached the Dnieper on September 18. Here, Lewenhaupt received the King's three messengers commanding him to cross the river and turn south toward the new rendezvous point, Starodub. For three days, the tired soldiers trundled their wagons across the river. As the last companies were crossing on the 23rd, Lewenhaupt became aware that a Russian force was moving against him; red-coated Russian cavalry began appearing on the fringes of the forest. Doggedly, he hurried on, making for the town of Propoisk on the River Sozh. Once across that stream, he would have a fair chance of reaching the main army intact.
It became a race. Lewenhaupt was desperately trying to reach Propoisk, but the muddy roads bogged his heavy wagons. On the morning of the 27th, the leading Russian cavalry caught up, and skirmishing with the Swedish rear guard began. Realizing that a major action was imminent, Lewenhaupt faced a choice: He could either leave his rear guard to hold off his pursuers as long as possible, sacrificing them if necessary, while pushing his main force and the baggage wagons forward in an effort to reach the Sozh, or he could halt his flight, stand and, with his whole force, fight. Being Lewenhaupt, he chose the second course. He sent the wagons ahead and brought the main body of his infantry and cavalry back down the road, drew them up in battle formation and awaited a Russian attack. There they stood through the morning and early afternoon of the 27th. Late in the afternoon, when it became clear that no Russian attack was coming, Lewenhaupt dissolved his battle line and fell back several miles along the road, then again drew up in line. His men stood in formation through the night.
The following morning, the 28th, when no attack had yet come, the Swedes again fell back, their columns skirmishing with the Russian horsemen who were all around them. They arrived at the village of Lesnaya, a short day's march from Propoisk. Now, the loss of time—almost the entire day of the 27th—revealed its importance. But for this fruitless day, the main body might have reached and crossed the Sozh to safety.
Nevertheless with the Russians clustered thickly around him, Lewenhaupt realized that he could not reach the river, and that he would have to fight. He sent 3,000 cavalrymen ahead to Propoisk to secure the river crossing and with the remaining 9,500 prepared for battle. He ordered a weeding out of the wagon train: colonels could keep four wagons, majors three, and so on.
On the opposite side, Peter dismounted his troops, dragoons and mounted infantry alike, and deployed them on the edges of the forest with Menshikov commanding the left wing with eight regiments, and Peter himself commanding the Preobrazhensky and Semyonovsky Guards and three dragoon regiments on the right wing. At one p.m. on the 28th, the battle began. It raged all afternoon, and, in Peter's words, "all day it was impossible to see where victory would lie." At one point, when Menshikov's troops were wavering, Peter reinforced them with the Semyonovsky Guards whose desperate counterattack restored the crumbling
Russian line. Soon after four p.m., Bauer arrived with his 3,000 dragoons to bolster the Russians, but this was balanced on the Swedish side by the return of the 3,000 cavalrymen who had been sent ahead to secure the ford and then been recalled. The battle continued until nightfall, when a sudden snowstorm, unusual for this early in autumn, obscured the combatants and brought the fighting to a halt. Although his lines were unbroken, Lewenhaupt ordered a retreat and the wagons burned. Like bonfires on wheels, the cartloads of supplies so laboriously pulled from Riga through 500 miles of mud and rain-soaked forest blazed through the night. The brass-and-iron cannon were lifted from their carriages and buried in pits dug in the earth to prevent the Russians from finding and capturing them. In the eerie light of the blazing wagons, confusion took hold and Swedish discipline disintegrated. Soldiers began plundering the wagons of officers' possessions and brandy. Units lost cohesion and stragglers stumbled off into the forest. Some of the infantry rode off on the horses freed from wagon yokes to Propoisk to cross the river to safety. When the surviving regiments arrived at Propoisk at dawn, they found the bridges burned. The few remaining wagons could not cross and they, too, were burned on the riverbank. At this point, a swarm of pursuing Cossacks and Kalmucks caught part of the disorderly Swedish mass on the riverbank and killed another 500 Swedes.
Morning broke over a Swedish disaster. The battle and the chaos of the night had cut Lewenhaupt's force in half. Of 2,000 cavalry, 1,393 remained; of 2,500 dragoons, 1,749 still were present; but of 8,000 infantry, only 3,451 remained. The total loss was 6,307 men; of these, over 3,000 were taken prisoner. Others wandered off into the forest alone or in small bands. Many died or were eventually captured. A thousand actually found their way back across Lithuania to Riga. All the supplies, clothes, food, ammunition, medicines which Charles so desperately needed were lost. On the Russian side, 1,111 were killed and 2,856 wounded. Each side had approximately 12,000 engaged; the Russians lost about one third, but the Swedes lost half.
Lewenhaupt led the bedraggled Swedish survivors—6,000 in all, now mounted on the wagon horses—down the road toward Severia. Peter, busy claiming the battlefield, did not pursue him, and ten days later Lewenhaupt finally joined the King. But what a disparity between what was expected and what arrived! Instead of a huge train of supplies to nourish the army, and 12,500 troops to reinforce it, Lewenhaupt brought 6,000 exhausted, nearly starving men, without artillery or supplies, straggling into camp. The cavalry units were kept together, but the infantry regiments were so shattered that they could no longer be maintained. They were disbanded, and the men used as replacements to fill gaps in the regiments of the main army.
On seeing the new arrivals, fresh gloom spread over the Swedish camp. The Battle of Lesnaya gave further evidence of the new fighting quality of the Russian army. The two sides had been almost equal in numbers, and the Swedes had lost. Nevertheless, Charles reacted to the defeat with equanimity. He did not criticize Lewenhaupt either for the slowness of his march or for the defeat. In fact, the King realized that he himself shared the blame: Having waited too long for Lewenhaupt, in the end he had not waited long enough.
On the Russian side, there was jubilation. The Russians believed that the Swedish force had been somewhat larger than their own— thus, that they had not only triumphed, but had triumphed against numerical odds. Peter, writing later, saw the importance in terms of the self-confidence of his men: "This victory may be called our first, for we have never had one like it over regular troops and then with numbers inferior to those of the enemy. Truly, it was the cause of all the subsequent good fortune of Russia and it put heart into our men, and was the mother of the Battle of Poltava."