Hanko Peninsula

Strategic setting

The Hanko Peninsula (Finnish: Hankoniemi; Swedish: Hangö udd), known in Russian sources as Gangut (Гангут), is the southernmost point of mainland Finland. A line drawn from the peninsula to the northwestern tip of mainland Estonia divides the Baltic Sea proper from the Gulf of Finland. The town of Hanko and the Port of Hanko stand on the peninsula, which is fringed by an archipelago. The Battle of Gangut was fought off these waters on 7 August 1714, and a Soviet naval base occupied the peninsula in the 1940s.

The sticking point of 1939

At the Moscow talks of October 1939 the Soviet side proposed an exchange: Finnish islands in the Gulf of Finland, the cession of the Rybachi Peninsula and of districts near Leningrad, and the lease of a naval and aviation base at Hanko with Soviet forces limited to four or five thousand men, in return for territory in Karelia. The Finnish representatives treated the island and Rybachi cessions as negotiable, but refused to let Soviet forces "touch" the Finnish mainland, knowing that a base at Hanko would be a pistol pressed into Finland's back. After the war broke out in November and Soviet demands grew, the Finnish delegation was forced to accept terms that included the base.

The Moscow Peace Treaty and the leased area

Under the Moscow Peace Treaty of 12 March 1940 Finland leased Hanko to the Soviet Union as a naval base for 30 years at an annual rent of 8 million marks. Railway transit rights were not part of the treaty; they were demanded separately in July. The area was handed over at midnight on 22 March 1940. Its inhabitants were given ten days to leave, and roughly 8,000 Finns lost their homes. The lease covered the town of Hanko together with surrounding waters and about 400 islands, 115 square kilometres in all. Soviet forces built a base with infantry, airborne and armoured units, coastal artillery and an airfield, while Finland fortified the boundary of the leased area with the Harparskog line.

The Continuation War and the evacuation

When the Continuation War began, Finnish troops isolated the base by land, but Mannerheim never authorized an assault. The Hanko front settled into trench warfare of artillery duels, sniping and patrols, with small amphibious actions in the archipelago and a Swedish Volunteer Battalion serving with the Finns. As the Baltic Fleet's position worsened in the summer of 1941, Hanko became an untenable burden, and the Soviet Stavka decided on evacuation on 23 October. Convoys ran from 16 October to 1 December 1941, carrying roughly 23,000 troops to Leningrad. The bulk of the garrison left on 2 December, and Finnish troops occupied the area on 4 December. Only a small Soviet garrison remained on the archipelago islands until 2 December 1941, holding out for nearly a month after the evacuation began.

Postwar settlement

In the Moscow Armistice of 19 September 1944 the Soviet Union gave up its Hanko lease and instead leased Porkkala for fifty years. The Hanko leased area was returned to Finland in 1944–1945, and the final turnover was set down in the Paris Peace Treaty of 1947.