The siege of Viborg took place in the spring of 1710 during the Great Northern War (1700–1721), as a second attempt by the Russians to capture the fortress port of Viborg, near the modern border between Russia and Finland, after a failed attempt in 1706. After the outbreak of the war, Swedish forces had fortified themselves in the port of Viborg. In order to assure safety for the newly founded city of Saint Petersburg, Peter the Great ordered the Swedish fort to be secured. A first unsuccessful attempt was made in 1706. Later plans were put on hold because of other ongoing conflicts but, after the Russian success at the Battle of Poltava in June 1709, the men and resources were available to capture the town.
Thirteen thousand troops under General-Admiral Fyodor Apraksin marched to Viborg and laid siege on 22 March 1710. Magnus Stiernstråle, the Swedish commander at the fort, waited in vain for Swedish assistance, while a stalemate ensued because the Russians lacked sufficient artillery. In April, Peter the Great managed to bring through a fleet of 250 ships to deliver guns and supplies, and to help perform a final assault on Swedish positions. After these Russian attacks, the Swedish garrison surrendered on 12 June 1710.
Background
After the victory at the Battle of Poltava, the Russian army was able to proceed with further offensive actions in the northwestern theater of operations. In 1710, the Russian army undertook an offensive in two directions: on the Baltic coast (where, in the fall in 1710, Riga was besieged) and in Finland, with attacks on Viborg and Kexholm. The selection of the command staff destined for the siege of Viborg led to the main authority being given to General-Admiral Fyodor Apraksin, while his subordinates were Major-Generals and Wilhelm Bergholtz. Before the siege, Bruce and Bergholtz had operated mainly in defensive roles, chiefly in the defense of Saint Petersburg. They would later lead the offensive into Finland. They were chosen because, at that time, the commanders most experienced in siege warfare (including Boris Sheremetev, Jacob Bruce, and Anikita Repnin) were concentrated around Riga. Consequently, it was considered a possibility that Peter the Great himself would command forces at Viborg, so that he would not have to reassign the experienced generals and thus jeopardize the attacks on Riga.
Fortifications at Viborg
In 1709, the main fort at Viborg consisted of five frontal bastions named Holtz, Neuport, Klein-Platform, Wasserport and Eleonora, connected by the Viborg town wall, in the eastern section of the town. The western part of the town, connected to the main section, had three bastions named Valport, Pansarlax, and Europa. To the west of the wall between Pansarlax and Europa, there was a ravelin and two caponiers, and to the west of the wall between Evrop and Eleonora was another ravelin. Both ravelins were, apparently, earthen, but inside the main eastern fort, all structures were stone. Most of the structures in the western part of the fort were wooden, with the exception of the stone guard tower, named the Petersburg tower. Separate from these fortifications, on the small central island west of the town (now the Zamkovy Island, ), was Viborg Castle, which stands to this day. The fort had 151 guns at its defense.
By this time, the fortifications had fallen into disrepair because the Swedish command did not pay much attention to these territories, and funds that were allotted for renovation were insignificant. In addition, the forts at Nöteborg and Nyenskans were considered sufficient to provide defense for the region. In 1702, however, some repairs were completed under the supervision of Captain L. Stobecks.
According to Yuri Moshnik, a modern historian, the garrison at Viborg in 1710 stood at 6000 men; other modern historians B. Adamovich and A. I. Dubravin put the number at 4000. Since 1702, the commander there had been Zacharias Animoff, who was old and in poor health. For that reason, in February 1710, Colonel Magnus Stiernstråle officially replaced him; he had de facto headed the efforts to fortify the city.