When Peter and his officers inside the town heard firing and saw the cavalry action on the bridge, they were unable to tell how many Swedes were upon them. Assuming that the entire Swedish army had arrived and that the bridge was now in its hands, Peter believed that Grodno could not be held. That night, while his troops evacuated the town, he kept his own carriage near the eastern gate. Before dawn, he climbed into it with Menshikov and rolled off in the direction of Vilna and St. Petersburg. If Charles had known of Peter's presence, he surely would have made a frenzied effort to capture this towering prize and change the nature of the war at a single stroke. As it was, Charles' horsemen approached the walls of Grodno the following morning, found them deserted and entered the town. But the drama was not over. At midday, on the road to Vilna, Peter learned the true nature of the sudden Swedish onslaught: that it. had been launched by a mere handful of men, that this same handful had occupied the town but had not yet been reinforced by the main Swedish army, and that among the Swedish band was Charles himself. He decided on a bold counterstroke: That night, he would launch his own surprise attack on the town to recapture it and, with luck, to seize the King of Sweden. The shamed Muhlenfels was dispatched back toward Grodno at the head of 3,000 cavalrymen with orders to attack after darkness.
Charles, with typical scorn for anything the Russians might do, had ordered that night that "all cavalrymen should off-saddle, undress and retire to rest." A watch of fifty dragoons was posted in a state of semi-alert, with horses saddled, to spend the night in houses along the road by which the Russians had evacuated Grodno. Of these fifty, a picket of fifteen men remained awake at the barrier across the road, but thirteen had dismounted and gathered around a fire to ward off the bitter cold of the January night. Only two mounted dragoons actually stood guard over the King of Sweden and his exhausted men, now all plunged deep into sleep.
After midnight, hundreds of Russian horsemen quietly approached the silent town. The sound of horses in the fields was picked up by the two dragoons on guard; they shouted to their comrades around the fire, who mounted in time to meet the first Russians at the barrier. Immediately, the other thirty-five dragoons came tumbling out of the houses, mounted their saddled horses and spurred into the fray. Although the Swedes were greatly outnumbered, the night was "so pitchy dark that none could see his hand before his face," and the Russians assumed that the force guarding the town would be much larger. Before many minutes passed, Charles and Rehnskjold both arrived, the King still in his stocking feet. They were eager to join in the melee, but unable in the darkness to distinguish friend from foe. A few minutes later, more Swedes arrived, some half dressed and riding bareback. Even in the blackness, the Russians sensed the growing reinforcement of their enemies and, unwilling to prolong the confused action, turned and retreated down the road they had come. Within an hour, Grodno was peaceful again. It was a fortunate and exhilarating night for Charles, who never stopped to ask himself what would have happened if Miihlenfels had adopted his own tactics and led 3,000 men in an impetuous dash into town, simply galloping past the two men on guard and the little group around die bonfire.
Charles remained for three days in Grodno alone with his small force of Horse Guards, but there was no further Russian attempt to retake the town. Muhlenfels, having failed twice, was arrested; the official charge was his failure to destroy the Neman bridge. When the main Swedish army began to arrive, the King put himself at the head of several elite regiments and set off in pursuit of Peter, but he was soon forced to give up the chase. His troops were too few and too tired, and the Russian scorched-earth tactics had reduced the countryside to a wintry desert.
In the days that followed, the Russian army withdrew entirely from the Neman River line, giving up its strong defense positions and its prepared winter quarters and retreating to a new line on the River Berezina. Charles followed, again riding ahead of his main army with his Guards cavalry. But the Swedish army was exhausted and needed rest. It had covered 500 miles and had already campaigned through almost three months of winter. The decisive factor was the lack of forage for the horses. The Russians had burned or the peasants had hidden what remained of the harvest; for the animals to survive, it was clear that the advance must halt until spring brought new shoots of green grass. On February 8, Charles halted, and when the main army joined them, he allowed them to camp and rest. On March 17, he moved again, shifting the camp to Radoshkovichi, northwest of Minsk. Here at last, in a triangle bounded by Vilna, Grodno and Minsk, the King placed the army in winter quarters.
The Polish campaign was over. On crossing the Neman at Grodno, the Swedish army entered Lithuania, the huge, sprawling, politically amorphous territory which lay between Poland, Russia and the Baltic. Three potentially formidable river barriers and the whole of Poland had been crossed with no more serious fighting than the cavalry skirmish at the Grodno bridge. The campaign had brought diplomatic as well as military fruits. In England, Queen Anne's government had been reluctant to grant recognition to Charles' puppet King of Poland, but when the news reached London of the ease with which Charles had advanced across Poland, Stanislaus was formally recognized as Augustus' successor. In Poland, those important members of the nobility who had withheld support from Stanislaus now moved to make amends. Throughout Western Europe, sovereigns and statemen gave Peter little chance. And among the Swedish soldiers, confidence in themselves and contempt for their enemies rose higher. What could one make of a Russian army commanded by the Tsar himself which would flee from a defended river line and a fortress town at the approach of only 600 Swedish horsemen?
Confinement in winter quarters was harder on the Swedish army than campaigning in the open field. Cramped into small, poorly heated rooms, without proper food, many of the soldiers, especially the new recruits from Sweden, caught dysentary, and some died. Charles himself suffered from the disease for several weeks. Outside, beyond the camp sentry posts, there was only the howling wind, the snow, the bitter cold, the ashes of burned villages, the scorched timbers of broken bridges fallen into frozen streams. Daily, Swedish foraging parties scoured the devastated landscape in search of food. They learned the Lithuanian peasant's habit of hiding his supplies in a hole in the ground and how to detect these secret caches by such signs as the quicker melting of the snow on top because of the warmth underneath. Often these foraging patrols encountered Russian cavalry, and skirmishes were constant. Ten or twenty horsemen would be in a clearing near a peasant hut when the Cossacks or Kalmucks would stumble upon them. Then there would be sudden shouts in the brittle winter air, a spurring of horses across the snow, a few shots and sword strokes before one side or the other was gone. It was a war without quarter, and the Swedes and these Russian irregulars hated each other. If either side captured the other, it locked its prisoners in a hut and burned it to the ground.
Through the wintry days, in the building used as army headquarters, Charles and his staff huddled over their maps. One day, while Gyllenkrook, his Quartermaster General, was working on his maps, "His Majesty came up to me and looked at my work and among other discourse he observed, 'We are now upon the great road to Moscow.' I replied that it was yet far hence. His Majesty replied, 'When we begin to march again, we shall get there, never fear.'" Gyllenkrook obediently turned back to his maps, preparing a line of march as far as Mogilev on the Dnieper, along the road to Smolensk and Moscow. To support the march, Charles summoned Count Adam Lewenhaupt, the Swedish commander in Riga, to Radoshkovichi. He ordered Lewenhaupt to scour Livonia and gather a vast amount of food, powder and ammunition along with the horses and wagons to transport it, and to be ready with his soldiers to escort this immense wagon train to a midsummer rendezvous point with the main army.