Finland wins the Battle of Tali-Ihantala, the largest battle ever fought in northern Europe - 1944

The Battle of Tali-Ihantala (June 25 to July 9, 1944) was part of the Finnish-Soviet Continuation War (1941–1944), which occurred during World War II. The battle was fought between Finnish forces—using war materiel provided by Germany—and Soviet forces. To date, it is the largest battle in the history of the Nordic countries.

Finnish soldiers of II division /infantry regiment JR 12 on Imatra road in Tali-Ihantala 30th June 1944. Behind them a soviet T-34 tank destroyed by a German assault gun

The Finns, though outnumbered 3 to 1, inflicted more than three times the number of casualties on the Soviet forces than they received. However, with just 50,000 men to the Soviets 150,000, the Finnish forces took proportionally more casualties.It marked a point in the Soviet offensive when the Finnish forces first prevented the Soviets from making any significant gains. Earlier at Siiranmäki and Perkjärvi the Finns had halted advancing Soviet forces. The Finnish forces achieved a defensive victory against overwhelming odds.

After the Soviets had failed to create any breakthroughs at Tali-Ihantala, Viborg Bay, or Vuosalmi, the Soviet Leningrad Front started the previously planned transfer of troops from the Karelian Isthmus to support Operation Bagration, where they were encountering particularly fierce resistance. Though the Leningrad Front failed to advance into Finland as ordered by the Stavka, some historians state that the offensive did eventually force Finland from the war.

Source: wikipedia