The 'Battle of Ilomantsi' was fought between Soviet and Finnish forces as part of the 'Svir-Petrozavodsk Offensive Operation' in what the Finns knew at the 'Jatkosota' (continuation war) (26 July/13 August 1944).
The battle took place in an area about 25 miles (40 km) wide and 18.5 miles (30 km) deep near the Finnish/Soviet border, close to the Finnish village of Ilomantsi in North Karelia. The battle ended with a Finnish victory in which the last major Soviet attack on Finland was stopped.
The Finnish forces in the area before the battle comprised only Eversti Torvald Ekman’s 21st Prikaati (brigade), but they were reinforced by the cavalrymen of Eversti Urho Tähtinen’s Ratsuväkiprikaati (cavalry brigade) and three other battalions (3rd Rajajääkäripataljoona and the two-battalion strong Osasto Partinen). All these Finnish forces were subordinated to a temporary formation named the Ryhmä Raappana (Raappana group) after its commanding officer, Kenraalimajuri Erkki Raappana, tasked with defeating the Soviet advance and retaking the key crossroads at the village of Kuolismaa.
During the initial Soviet push the sole Finnish unit delaying the Soviets was the 7,000-man 21st Prikaati, but as the front father to the south in the Karelian isthmus was stabilised the Ratsuväkiprikaati was rushed to Ilomantsi to reinforce the 21st Prikaati, bringing the Finnish strength on 31 July, when the counterattack began, to about 13,000 men.
The forces of Marshal Sovetskogo Soyuza Kyrill A. Meretskov’s Karelian Front advancing towards Ilomantsi comprised two divisions of General Leytenant Filip D. Gorelenko’s 32nd Army. These formations were Polkovnik Vasili I. Zolotarev’s 176th Division and General Major Tsernuha’s 289th Division. As the battle progressed and the advancing divisions were encircled, the Soviet forces in the area were reinforced by the 3rd, 69th and 70th Naval Brigades and other units.
According to Soviet archives, at the beginning of the Karelian Front’s 'Svir-Petrozavodsk Offensive Operation' on 21 June, the two Soviet divisions had a combined strength of some 16,000 men. By the time that the Finnish counterattack at Ilomantsi started on 31 July, the two division’s strength had dropped to 11,000 men. After the 3rd, 69th and 70th Naval Brigades had been brought up to support the encircled 176th and 289th Divisions, the combined Soviet infantry strength at Ilomantsi was slightly greater than 20,000 men.
At first, the Soviet offensive seemed to be successful as on 21 July Soviet units had been able to reach the 1940 Finnish/Soviet border for the only time during the entire Soviet offensive of 1944. Finnish reinforcements arrived on 28 July, and on 31 July Raappana started his North Karelia counterattack. By 1 August the Finns had already cut the sole road providing overland communication with the 176th Division and by 3 August both Soviet divisions had been encircled as the Finnish forces utilised their now fully developed envelopment tactics to outflank their opponents and trap them in motti positions. Men of the 4th Erillinen Pataljoona disrupted the supply lines nourishing the Soviet artillery, preventing effective fire support.
The Soviets deployed three brigades with armour support in their efforts to reopen the road connections to the encircled divisions, but the Finns prevented any such success. Renewed Soviet attacks then distracted the Finns sufficiently to make it possible for the encircled Soviet forces to escape through the dense forests of the region, although only after abandoning their heavy equipment. Given the element of surprise and as a result of the Soviets' superior numbers, the Finnish troops trapping the encircled divisions had little hope of containing organised break-outs, especially in the forests, and so many of the encircled Soviets managed to escape to their own side, the last of them escaping on 10 August.
The Utrio area played a central role in Raappana’s planning. Fast-moving battalions of the Ratsuväkiprikaati, highly experienced in forest warfare, drove through this area between lakes to create a wedge between the 176th Division and 289th Division. The opening battles fell on the Finns' 6th Jääkäripataljoona. When it implemented the encirclements at Leminaho and Lutikkavaara hill, the 'Uusimaa' Dragoon Regiment attacked through Utrio and across the Ruukinpohja river, with flanking support by the 1st Jääkäripataljoona.
The two Soviet divisions were decimated in this last major engagement on the Finnish front before the armistice was concluded early in September 1944.
Military historians note that the two Soviet divisions were completely routed after some 10 days of fighting, leaving behind more than 3,200 men killed, thousands of wounded and missing, and more than 100 pieces of heavy artillery, about 100 mortars and the rest of the Soviet lighter ordnance for the Finns to seize.
The 'Battle of Ilomantsi' This was the ninth major Finnish defensive victory in a period of only a few weeks following the Soviet offense launched against the Finns in June 1944.
In 10 days, the forces under Raappana’s command had fired more than 36,000 artillery shells at the Soviet forces. The Soviet artillery at Ilomantsi had been able to fire only 10,000 shells during the same period. The main reason for the poorer Soviet artillery outcome was the Finnish disruption tactics: for instance, a Finnish guerrilla detachment led by Luutnantti Heikki Nykänen, destroyed a Soviet convoy of 30 trucks carrying artillery rounds to the battle scene.
The Finns had achieved victory, and the remnants of the two Soviet divisions only just escaped total destruction by breaking out from the encirclements.