The Sinyavino offensive (or third Sinyavino offensive) was an operation planned by the Soviet Union in the summer of 1942 with the aim of breaking the siege of Leningrad, which had begun the previous summer, and establish a reliable supply line to Leningrad. At the same time, German forces were planning Operation Northern Light () to capture the city and link up with Finnish forces. To achieve that heavy reinforcements were arriving from Sevastopol, which the German forces captured in July 1942. Both sides were unaware of the other's preparations, and this made the battle unfold in an unanticipated manner for both sides. The Soviet offensive began first in two stages. The Leningrad Front began the offensive on 19 August and the Volkhov Front launched the main offensive on 27 August. From 28 August the German side shifted the forces which were building up for their own offensive to gradually halt the Soviet offensive. Initial German counterattacks failed, but the Soviet forces could not advance either. After a ten-day stalemate, the significantly reinforced Germans launched a counterattack against the Soviet forces on 21 September. After five days of heavy fighting, the German forces linked up and cut off the bulge formed by the Soviet offensive. By 10 October the front line returned to the position before this battle; heavy fighting continued until 15 October, as the last pockets of Soviet resistance were destroyed or broke out. In the end, the Soviet offensive failed, but heavy casualties caused the Germans to order their forces to assume a defensive stance. In November, the German reinforcements and other units were stripped from Army Group North to deal with the major Soviet offensive at Stalingrad and Operation Northern Light was aborted. Background The siege of Leningrad started in early autumn 1941. By 8 September 1941 German and Finnish forces had surrounded the city, cutting off all supply routes to Leningrad and its suburbs. However, the original drive on the city failed and the city was subjected to a siege. During the winter 1941–42, the city was partially supplied via the Road of Life over the frozen Lake Ladoga, which allowed the defenders to continue holding out. However, after the siege of Sevastopol ended on 4 July 1942, with the German capture of the city, the German 11th Army was free to be used elsewhere, and Hitler decided that the 11th Army would be used