Following the successes against the Germans during 1943 and the beginning of 1944, Soviet Union launched the fourth of its ten strategic attacks on June 9th 1944, north east of Leningrad. The largest Soviet offensive of 1944 was timed to support of the western allies, who had landed in Normandy three days earlier. The objective of the Soviet attack was to force Finland out of the war and ultimately conquer it.

The Soviet Air Force (VVS) threw a formidable force against the Finns. 'The Great Attack', as it became known in Finland, was supported by more than 250 bombers and 1000 fighter- and strike aircraft from Lt.General Rybaltschenko's 13th Air Army (13 VA), with a further 220 from the Soviet Red Banner Baltic Fleet Air Force (VVS KBF). The Soviets had over 1500 aircraft supporting the ground attack wedge, not more than 20 kilometers wide at any given point.

Opposing the Soviet armada over the Karelian Isthmus were Lt.Colonel Magnusson's Flight Regiment 3 (LeR 3) and Lt.Colonel Joensuu's Flight Regiment 4 (LeR 4) of the Finnish Air Force. Equipped with only 30 Messerschmitt 109 G's, 18 Brewsters and 53 bombers, of which only 12 were modern Ju 88's, the Finns faced even worse odds than during the Winter War four years earlier.

Also on the ground, the Soviet Union enjoyed a superiority both in numbers and the quality of equipment. During the spring months, the Soviets had made meticulous preparations and had 270 000 men, 1800 artillery pieces and 600 tanks in attack positions. Across the border in poorly fortified installations the 70 000 Finnish defenders, equipped with 300 artillery pieces, 100 tanks and practically no anti-tank weapons, were ill prepared for the upcoming onslaught. Battle-hardened during 3 years of fighting against Germany, the Soviet armed forces posed a serious threat to the existence of Finland as a nation.

As the Soviet attack begun, the Finns immediately contacted Germany and sent a desperate request for help. Germany agreed to sell more Messerschmitts and anti-tank infantry weapons to the Finnish armed forces. In addition, German combat units were sent to Finland. Less than a week after the attack had begun, Gefechtsverband Kuhlmey arrived, a Luftwaffe combat group consisting of some 70 Stukas and Focke Wulf jabos, more than doubling the ground attack capability of the Finnish Air Force. In addition, several German infantry and tank units arrived to help in the struggle to maintain Finland's independence.

On the Karelian Isthmus, the Finns had three main defensive lines: the main line, VT-line and VKT-line. The main defensive positions on the border were in many places poor, with the terrain giving no natural cover for the defenders. The Vammelsuu-Taipale (VT) -line was the first well fortified position, located approximately 20 kilometers from the frontline. The fortifications of the Viipuri-Kuparsaari-Taipale (VKT) -line had only started and were still unfinished, but the rocky terrain at the VKT-line favoured the defender.

The flat landscape and good roads of the western Karelian Isthmus favoured the attacker's mobile units and heavy use of tanks. Breaking through the VKT-line would open a direct passage to the southeastern plains and all the way to Helsinki, the capital of Finland...