The Battle of the River Plate was the first naval battle in the Second World War and the first one of Battle of the Atlantic in South American waters. The German cruiser Admiral Graf Spee had been located in the South Atlantic a long time before the war began, and had been commerce raiding after the war began in September 1939. One of the hunting groups sent by the British Admiralty to search for Graf Spee, comprising three Royal Navy (RN) cruisers, HMS Exeter, Ajax and Achilles (the last from the New Zealand Division), found and engaged their quarry off the estuary of the River Plate close to the coast of Argentina and Uruguay in South America.
In the ensuing battle, Exeter was severely damaged and forced to retire; Ajax and Achilles suffered moderate damage. The damage to Graf Spee, although not extensive, was critical; her fuel system was crippled. Ajax and Achilles shadowed the German ship until she entered the port of Montevideo, the capital city of neutral Uruguay, to effect urgent repairs. After Graf Spee’s captain Hans Langsdorff was told that his stay could not be extended beyond 72 hours, he scuttled his damaged ship rather than face the overwhelmingly superior force that the British had led him to believe was awaiting his departure.