War of the Lakes

The War of the Lakes, also known as the Second Novgorod War, was a war between Sweden and Novgorod over Lake Ladoga and other Finnish lakes.

Background
Sweden had beaten Novgorod previously in the Novgorod War; the latter had made large concessions, including their capital Veliky Novgorod. The lands directly to the east of Finland, however, remained a part of Novgorod. On 14 September 1459, the province of Olonets was claimed by Sweden, signalling a possible second invasion. No action was taken until the war.

The War
On 14 April 1465, King Gustav II Drake of Sweden announced that Sweden would go to war to Novgorod again, and justified it with the following statements:
 * The eastern Finnish border remains unprotected, especially from Muscovite interference.
 * If Muscovy were to take down all of Novgorod, their power would grow exponentially (this has remained a major factor in Swedish peace deals - for instance, the crown went out of the way to take Veliky Novgorod i.e. Gustavstad to prevent Muscovy from claiming the title of Russia, thus magnifying their prestige and power)
 * Novgorod wrests Swedish trade power in the Gustavstad area, reducing potential income.

Swedish troops moved into Kexholm the day war was declared, and quickly split to take down the nearby provinces of Karelia and Olonets. As expected, shortly after Sweden declared war, Muscovy did so as well. The main group of Swedish troops then quickly raced to Soroka, the Novgorodian capital, but were beaten by Muscovite forces. The focus then shifted to chasing down Novgorodian troops who attempted to siege down the countryside. The troops were finally confronted in Halsingland on 24 January 1466, and the Novgorodians were completely destroyed. A smaller group was later confronted and also killed. The war was practically decided from that point.

End
After Muscovy took Soroka and Onega in the war, Sweden followed with the Treaty of Linkoping. Novgorod ceded Karelia, Kexholm, and Olonets, and the remainder of the country was vassalized.