The Continuation War was a conflict fought by Finland and Nazi Germany against the Soviet Union during WWII, from the Finnish declaration of war (25 June 1941) to the Moscow Armistice (19 September 1944). In summer 1944, after withdrawing from earlier positions near Karhumäki, Colonel Torvald Ekman’s Finnish 21st Brigade conducted a fighting retreat towards the old Finland-Russia border south of Ilomantsi.

The General Headquarters issued an order for the establishment of a temporary formation to stop, encircle and destroy the enemy forces advancing toward Ilomantsi. The task was assigned to Major General Erkki Raappana, who had commanded the 14th Division in Rukajärvi sector since the outbreak of the war.

The 21st brigade then moved into preselected positions around Öykkösenvaara, where terrain offered clear defensive advantages.

Steep, rocky hillside allowed defensive works to be built on several levels. A single narrow road approached the position between bodies of water, restricting movement and funnelling any attack into a confined corridor. These natural features influenced how the defensive system was designed and how the battle later unfolded.

From late July 1944, close to 1000 men worked to prepare the position. Among them were skilled explosive handlers and reservists who had received sapper training. They were assisted by convicts in forced labour service and men relieved from combat duties for various reasons. They dug rifle pits, constructed covered dugouts and laid obstacles. Plans also included reinforced gun emplacements near the hill crest, but these were not fully completed before the first elements of the Soviet 289th Division reached the area on 29 July 1944.

When Soviet troops attempted to advance, they faced concentrated fire from well-prepared Finnish positions. Units of 21st Brigade engaged the attackers with small arms, while mortars, artillery and a 45-millimetre anti-tank gun supported the defence. Mines placed along the roadway caused significant damage to Soviet motorised units and eventually made the route unusable for further advance and supply. Repeated attempts to push forward failed under this combined defensive fire.

In early August the Soviet command ordered a withdrawal from the area. However, Soviet units became encircled by Finnish troops. Only parts of these formations managed to withdraw eastwards, after abandoning equipment. The fighting around Öykkösenvaara formed part of the wider actions on the Ilomantsi front that halted the Soviet offensive in this region.

The battle of Ilomantsi had an important effect on the outcome of the war. It forced Red Army high command to discard its strategic objective of forcing Finland to accept an unconditional surrender.