In the middle of the XVIIth century the fortress became the seat of the Poltava Cossack Regiment and played a strategic role in the system of Ukrainian defensive installations that were erected to protect this region from the invasion of Baty-Khan. In 1658, soon after the signing of the Treaty of Pereyaslav, the fortress was partially reconstructed under the supervision of the Muscovite voevode Chirkov. On the eve of the decisive battle of the Great Northern War, the fortress was surrounded by ravines, protected by palisades, and had many bastions and five gates, which were protected by special towers to secure the approach roads to the fortress. But if one compares it with some other European fortresses of that time, its imperfection becomes clear.

On the eve of the battle, when Tsar Peter was informed that Hetman Mazepa was in the camp of the Swedish king, he ordered that the fortress’ commandant Col. Levenets, a supporter of Mazepa, be placed under house arrest in Kharkov and replaced by Col. Kelin. Three infantry battalions loyal to the Tsar were also deployed in the fortress to reinforce it.

One of the numerous myths common among first Russian and then Soviet historians is that of a “heroic defence of the fortress in April–May 1709”. In Poltava there is a monument to the commandant Kelin and “brave defenders of the fortress of Poltava”, which was unveiled in 1909 in the presence of Tsar Nikolay II. But, in reality, there were no attempts to take the fortress, because the Swedes had besieged it for the sole purpose of forcing Peter I to engage in a decisive battle. A lieutenant of the Dalecarlia Regiment, Robert Petre, who during the siege was in command of a platoon deployed in approach trenches near the eastern sector of the fortress, left a diary, which has been published in Sweden. The most interesting entries in it concern a dialogue between Charles XII and the commander of the siege artillery, Col. von Binau, overheard by the lieutenant. The colonel wanted the king to give his two batteries just six hours to raze the fortress to the ground, but the king turned him down politely although there was enough ammunition. It is hard to believe that the experienced Swedish army was unable to conquer this primitive defensive installation that had no stone wall and only a few guns.

The fortress of Poltava was repaired for the last time in the late 1720s. After the signing of the Russian-Turkish peace treaty of 1774, the border of the Russian Empire was moved further south and Poltava fortress started to lose its significance. At that time the name for Ukraine introduced by Moscow was “Little Russia”. In the nineteenth century, when Poltava became a central city of Malorossiyskaya (Little Russia) government, new streets in many places breached the fortress’ earthworks. On the eve of Tsar Alexander I’s visit to Poltava in 1817 all the remains of the fortress were razed to the ground. This fact aroused his displeasure, because at that time it was absolutely clear that the Russian Empire had a firm intention to use Poltava as a symbol of its power and celebrate no other historic victories, but only victory over the Swedes in 1709.