The Siege of Vyborg 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 town of Vyborg after a failed attempt in 1706. After the outbreak of the war, Swedish forces had fortified themselves in the port of Vyborg. In order to assure safety for the newly founded city of Saint Petersburg, Peter the Great ordered the Swedish fort to be secured. These 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.