 During World War II , Northcott was attached to the British 7th Armoured Division in the Middle East to study armoured warfare , returning to Australia in December 1941 to organise the new 1st Armoured Division . In March 1942 , he assumed command II Corps . In September 1942 , he was appointed Chief of the General Staff . As General Sir Thomas Blamey 's principal non @-@ operational subordinate , he was responsible for administering and training the wartime army . After the war , he served as commander of the British Commonwealth Occupation Force in the post @-@ war Occupation of Japan . He retired from the Army in 1946 to become the Governor of New South Wales . 
