Battle of Hanko (1941)
Encyclopedia
The Battle of Hanko was a lengthy series of small battles fought on Hanko Peninsula
during the Continuation War
between Finland and the Soviet Union in the second half of 1941. As both sides were eager to avoid a major, costly ground battle, fighting took the form of trench warfare, with artillery exchanges, sniping, patrol clashes, and small amphibious operations performed in the surrounding archipelago. A volunteer Swedish
battalion served with Finnish forces in the siege. The last Soviet troops left the peninsula in December 1941.
, Hanko was leased to the Soviet Union
as a naval base. The civilian population was forced to evacuate before Soviet forces arrived. The leased area included several surrounding islands, several coastal artillery sites (among them the important fort of Russarö
), important harbor facilities, and an area suitable for an airfield, which the Soviets quickly constructed. Troop transport rights from the Soviet Union to Hanko and back put severe strain on Finnish-Soviet relations, and played a part both in Finland's decision to allow German troops to transit Northern Finland, and later, to go to war with the Soviet Union. Though Hanko had originally been leased as a naval base, ground forces were far more numerous, with only a small naval detachment being present at the base.
, they moved to occupy these positions. The front remained mostly static, with action consisting mainly of artillery strikes and some limited probing or patrol activities on both sides. Small scale naval and amphibious actions took place in the surrounding archipelago. Finnish forces surrounding the base initially consisted of the 17th Division, the 4th Coastal Brigade, and supporting units. By the end of the summer, the 17th Division, which had made up the bulk of the besieging force, was transferred to East Karelia.
Finnish efforts to blockade the base from the sea were less successful, due both to strong Soviet resistance, and to equipment failures (such as torpedoes used by Finnish submarines, which often failed to detonate on impact). Minefields laid on the sea lanes leading to Hanko and the surrounding waters were more effective, claiming several Soviet supply vessels. These problems, in addition to the rapid German
advance on the southern shore of the Gulf of Finland
, caused the base to lose its importance and made it an untenably heavy burden for the Soviet Baltic Fleet
. In autumn 1941 the order was given to evacuate Hanko. Base personnel, troops and most of their light equipment and supplies had been removed by December 1941. Heavier equipment which couldn't be readily moved was sabotaged or destroyed in place. Soviet naval forces performing the evacuation suffered heavy losses from minefields.
The Soviet base at Hanko, its accompanying coastal fort at Osmussaar
, and the minefields laid to protect the Soviet Baltic Fleet
had hindered Finnish and German naval activities, and had made it problematic for freighters to reach the Finnish ports of Helsinki
and Kotka
. As Finland lacked the resources to transport enough goods over land this caused severe logistical problems, with material stuck in seaports on the Western coast. Finnish and German minesweepers had opened a sea-lane through the minefields outside of the gun range of Russarö to allow freighters to reach even the Eastern ports, but it wasn't until the Soviet evacuation that they were able to clear the more secure coastal sea-lane, allowing safer passage.
, which had a lighthouse and was thus an important observation post. The initial landing, performed in the middle of the night in foggy conditions, was successful, as Finnish sentries believed the approaching boats to be German minesweepers; however, the small garrison recovered quickly. Putting up fierce resistance, the Finns managed to retain control of the lighthouse while summoning help from nearby naval forces and coastal artillery. The fighting continued throughout the night. In the morning Finnish reinforcements were able to force the remaining Soviet raiders to surrender and drive their naval support away.
) as well as several smaller vessels. Finnish troops entering the area found it heavily mined.
Hanko Peninsula
The Hanko Peninsula , also spelled Hango, is the southernmost point of mainland Finland. The soil is a sandy moraine, the last tip of the Salpausselkä ridge, and vegetation consists mainly of pine and low shrubs...
during the Continuation War
Continuation War
The Continuation War was the second of two wars fought between Finland and the Soviet Union during World War II.At the time of the war, the Finnish side used the name to make clear its perceived relationship to the preceding Winter War...
between Finland and the Soviet Union in the second half of 1941. As both sides were eager to avoid a major, costly ground battle, fighting took the form of trench warfare, with artillery exchanges, sniping, patrol clashes, and small amphibious operations performed in the surrounding archipelago. A volunteer Swedish
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
battalion served with Finnish forces in the siege. The last Soviet troops left the peninsula in December 1941.
Background
As part of the 1940 Moscow Peace Treaty which formally ended the Soviet-Finnish Winter WarWinter War
The Winter War was a military conflict between the Soviet Union and Finland. It began with a Soviet offensive on 30 November 1939 – three months after the start of World War II and the Soviet invasion of Poland – and ended on 13 March 1940 with the Moscow Peace Treaty...
, Hanko was leased to the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
as a naval base. The civilian population was forced to evacuate before Soviet forces arrived. The leased area included several surrounding islands, several coastal artillery sites (among them the important fort of Russarö
Russarö
Russarö is an island south of Hanko. The island is closed to the public as it is military area of the Finnish Defence Forces. The island has a five-story stone lighthouse built in 1863 and a Finnish Meteorological Institute weather station.- External links :...
), important harbor facilities, and an area suitable for an airfield, which the Soviets quickly constructed. Troop transport rights from the Soviet Union to Hanko and back put severe strain on Finnish-Soviet relations, and played a part both in Finland's decision to allow German troops to transit Northern Finland, and later, to go to war with the Soviet Union. Though Hanko had originally been leased as a naval base, ground forces were far more numerous, with only a small naval detachment being present at the base.
Operations
At the start of the war, Finnish ground troops quickly isolated Hanko and its 30,000-man Soviet garrison. Though Mannerheim initially declared that liberating Hanko would be a primary goal of the war, Finnish troops in the area did not receive authorization to attack the base. Instead, as the Finns had built a series of fortifications on the border of the leased area during the Interim PeaceInterim Peace
The Interim Peace was a short period in the history of Finland during the Second World War. The term is used for the time between the Winter War and the Continuation War, lasting a little over a year, from 13 March 1940 to 24 June 1941...
, they moved to occupy these positions. The front remained mostly static, with action consisting mainly of artillery strikes and some limited probing or patrol activities on both sides. Small scale naval and amphibious actions took place in the surrounding archipelago. Finnish forces surrounding the base initially consisted of the 17th Division, the 4th Coastal Brigade, and supporting units. By the end of the summer, the 17th Division, which had made up the bulk of the besieging force, was transferred to East Karelia.
Finnish efforts to blockade the base from the sea were less successful, due both to strong Soviet resistance, and to equipment failures (such as torpedoes used by Finnish submarines, which often failed to detonate on impact). Minefields laid on the sea lanes leading to Hanko and the surrounding waters were more effective, claiming several Soviet supply vessels. These problems, in addition to the rapid German
Operation Barbarossa
Operation Barbarossa was the code name for Germany's invasion of the Soviet Union during World War II that began on 22 June 1941. Over 4.5 million troops of the Axis powers invaded the USSR along a front., the largest invasion in the history of warfare...
advance on the southern shore of the Gulf of Finland
Gulf of Finland
The Gulf of Finland is the easternmost arm of the Baltic Sea. It extends between Finland and Estonia all the way to Saint Petersburg in Russia, where the river Neva drains into it. Other major cities around the gulf include Helsinki and Tallinn...
, caused the base to lose its importance and made it an untenably heavy burden for the Soviet Baltic Fleet
Baltic Fleet
The Twice Red Banner Baltic Fleet - is the Russian Navy's presence in the Baltic Sea. In previous historical periods, it has been part of the navy of Imperial Russia and later the Soviet Union. The Fleet gained the 'Twice Red Banner' appellation during the Soviet period, indicating two awards of...
. In autumn 1941 the order was given to evacuate Hanko. Base personnel, troops and most of their light equipment and supplies had been removed by December 1941. Heavier equipment which couldn't be readily moved was sabotaged or destroyed in place. Soviet naval forces performing the evacuation suffered heavy losses from minefields.
The Soviet base at Hanko, its accompanying coastal fort at Osmussaar
Osmussaar
Osmussaar is an Estonian island situated in the mouth of the Gulf of Finland in the Baltic Sea, 7.5 km off the Estonian mainland. Administratively the island is part of Noarootsi Parish in Lääne County. Its area is ....
, and the minefields laid to protect the Soviet Baltic Fleet
Baltic Fleet
The Twice Red Banner Baltic Fleet - is the Russian Navy's presence in the Baltic Sea. In previous historical periods, it has been part of the navy of Imperial Russia and later the Soviet Union. The Fleet gained the 'Twice Red Banner' appellation during the Soviet period, indicating two awards of...
had hindered Finnish and German naval activities, and had made it problematic for freighters to reach the Finnish ports of Helsinki
Helsinki
Helsinki is the capital and largest city in Finland. It is in the region of Uusimaa, located in southern Finland, on the shore of the Gulf of Finland, an arm of the Baltic Sea. The population of the city of Helsinki is , making it by far the most populous municipality in Finland. Helsinki is...
and Kotka
Kotka
Kotka is a town and municipality of Finland. Its former name is Rochensalm.Kotka is located on the coast of the Gulf of Finland at the mouth of Kymi River and it is part of the Kymenlaakso region in southern Finland. The municipality has a population of and covers an area of of which is water....
. As Finland lacked the resources to transport enough goods over land this caused severe logistical problems, with material stuck in seaports on the Western coast. Finnish and German minesweepers had opened a sea-lane through the minefields outside of the gun range of Russarö to allow freighters to reach even the Eastern ports, but it wasn't until the Soviet evacuation that they were able to clear the more secure coastal sea-lane, allowing safer passage.
Amphibious operations
Both Finnish and Soviet coastal forces conducted numerous small-scale amphibious operations in the archipelago surrounding the Hanko Peninsula. The first of the these clashes took place at the beginning of July 1941; active operations ended the following October. Fighting on these small islands was often fierce, and withdrawing from them under fire was extremely hazardous. In general the operations had little effect on the overall battle, as territorial gains remained negligible.Battle of Bengtskär
After capturing the small island of Morgonlandet in July 1941, Soviet forces launched a small-scale amphibious assault against the Finnish island of BengtskärBengtskär
Bengtskär is a skerry southwest of Hanko, and part of the municipality of Dragsfjärd. This rocky skerry is the southernmost inhabited place in Finland, and is reached by ferry from the village of Kasnäs....
, which had a lighthouse and was thus an important observation post. The initial landing, performed in the middle of the night in foggy conditions, was successful, as Finnish sentries believed the approaching boats to be German minesweepers; however, the small garrison recovered quickly. Putting up fierce resistance, the Finns managed to retain control of the lighthouse while summoning help from nearby naval forces and coastal artillery. The fighting continued throughout the night. In the morning Finnish reinforcements were able to force the remaining Soviet raiders to surrender and drive their naval support away.
Evacuation
The evacuation of Hanko was performed in several convoys, which managed to transport roughly 23,000 troops to Leningrad. The fleet suffered casualties from Finnish minefields and coastal artillery, losing 3 destroyers and 2 large transports (Andrei Zhdanov and Iosif StalinIosif Stalin class passenger ship
The Iosif Stalin-class passenger ship was a two-strong class of large turbo-electric powered passenger ships, operated by the Soviet Baltic State Shipping Company . The ships were taken over by the Soviet Navy during World War II and used as transport vessels...
) as well as several smaller vessels. Finnish troops entering the area found it heavily mined.