The Battle of Hanko (also known as the Hanko Front or the Siege 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.