In May, the Swedes started besieging Poltava’s fortress. The main Russian army was closing in, but it needed to cross the Vorskla River. The Swedes attempted to block the Russians from crossing, but Swedish king Charles XII was wounded. Without him, the Swedish command was paralyzed. Unopposed, a few days later the Russians crossed over.
As the Russians approached Poltava, an opportunity to attack them arose. With Charles XII still wounded, no decision to attack was made (A). The Russians started to build a fortified camp near to the Swedes. The Swedes were still divided on whether to attack while the camp was being built or to wait (B1). With the camp completed, the Russians started a series of small redoubts. The Swedes could have launched an attack at this point (B2) but did not. A conference was held on the evening when the small redoubts were started. Despite the king still being unable to lead the army in person, the Swedes decided that they would march that night to attack the Russian redoubts (C1). Night attacks were notoriously difficult and risky; the same attack in daylight would have been possible (C2).
It was decided to leave a strong garrison in the camp, to leave the siege lines occupied and not to withdraw outlying troops. This meant leaving the majority of the artillery behind. While done for good reasons, it meant that the night attack force that marched was reduced (D).
Unknown to the Swedes, the Russians had not only completed the original small redoubt but even built more. The night march blundered into these and managed to break through the redoubts. Once through, a large cavalry
