The war began on February 21, 1808, when Russian troops crossed the border at Ahvenkoski into Finland, which was then a province of Sweden. That evening they captured the town of Loviisa, without a formal declaration of war.
That set off a year and a half of fighting, which ended on September 17, 1809. Finland then became an autonomous Grand Duchy under the Russian crown -- until independence in 1917.
On Thursday, history buffs in Ahvenkoski and Loviisa will stage reenactments of the day's events.
Meanwhile in Espoo, historians begin a three-day conference on Thursday, aimed at placing the War of Finland in a broader European context of the Napoleonic Wars. Prime Minister Matti Vanhanen will deliver the opening address.