He also served in the Second World War initially as Third Sea Lord and Controller of the Navy and then as second-in-command and afterwards as commander of the Home Fleet, leading the force that destroyed the German battleship Scharnhorst.

He went on to be First Sea Lord and Chief of the Naval Staff in which role he assisted in establishing NATO and agreed to the principle that the Supreme Allied Commander Atlantic should be an American admiral, in the face of fierce British opposition.

[2] Fraser served in the First World War, initially in the cruiser HMS Minerva providing naval gunfire support during the Gallipoli Campaign and then carrying troops to protect Egypt's Western frontier.

[2] After the war and following his promotion to commander on 30 June 1919 and his appointment as an Officer of the Order of the British Empire on 17 July 1919,[5] Fraser volunteered to serve with the White Russian Caspian Flotilla; however on arrival in Azerbaijan as part of the 1920 Royal Navy Mission to Enzeli, he was captured and imprisoned by Bolsheviks in the Black Hole of Baku until released in November 1920.

[6] Promoted to vice admiral on 8 May 1940,[11] he was advanced to Knight Commander of the Order of the British Empire in the 1941 Birthday Honours[12] and became second-in-command, Home Fleet and Flag Officer, 2nd Battle Squadron, in June 1942.

[8] In the role of Commander-in-Chief of the Home Fleet, he commanded the Royal Navy force that destroyed the German battleship Scharnhorst at the Battle of the North Cape on 26 December 1943.

[23] As First Sea Lord he assisted in establishing NATO and agreed to the principle that the Supreme Allied Commander Atlantic (SACLANT) should be an American admiral, in the face of fierce British opposition.