December 12, 1939

1939HMS Duchess sinks after a collision with HMS Barham off the coast of Scotland with the loss of 124 men.^[†]

HMS Duchess was a D-class destroyer built for the Royal Navy in the early 1930s. The ship was initially assigned to the Mediterranean Fleet before she was transferred to the China Station in early 1935. She was temporarily deployed in the Red Sea during late 1935 during the Abyssinia Crisis, before returning to her duty station where she remained until mid-1939. Duchess was transferred back to the Mediterranean Fleet just before the Second World War began in September 1939. While escorting the battleship HMS Barham back to the British Isles, she was accidentally rammed by the battleship in thick fog and sank with heavy loss of life on 12 December 1939.

1939Winter War: The Battle of Tolvajärvi, also known as the first major Finnish victory in the Winter War, begins.^[†]

The Winter War was a war between the Soviet Union and Finland. It began with a Soviet invasion of Finland on 30 November 1939, three months after the outbreak of World War II, and ended three and a half months later with the Moscow Peace Treaty on 13 March 1940. Despite superior military strength, especially in tanks and aircraft, the Soviet Union suffered severe losses and initially made little headway. The League of Nations deemed the attack illegal and expelled the Soviet Union from its organization.