World War II: Battle of the Atlantic: HMS Venturer sinks U-864 off the coast of Fedje, Norway, in a rare instance of submarine-to-submarine combat.

The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allied naval blockade of Germany, announced the day after the declaration of…