Born in 1895, Hanson joined the New Zealand Expeditionary Force during the First World War and served on the Western Front.

Ending the war with the rank of brigadier, he returned to civilian life as the chief engineer of the Main Highways Board.

[2] In 1915, Hanson passed the entrance examination for the Royal Military College, Duntroon, in Australia, which set aside a limited number of enrolments for New Zealanders.

In January 1940, with the rank of major, he was posted to command of 7th Field Company, New Zealand Engineers, for which officers and non-commissioned officers began a period of training at Narrow Neck Camp, in Auckland, before the main body of the company arrived at the nearby Papakura Military Camp.

[5] Within a matter of weeks, the 2nd New Zealand Division was in Greece and manning defences on the Aliakmon Line[6] in preparation for the anticipated invasion of the country by the Germans.

[7] During the subsequent retreat of the Allies following the commencement of the German advance into Greece, Hanson's command was often involved in delaying tactics through the destruction of strategic points.

[8] The airfield subsequently fell to German forces once their invasion of Crete began on 20 May and it proved crucial in allowing reinforcements and supplies to be landed in the early stages of the battle.

[9] At one stage, Hanson was involved in an attack, the Battle of 42nd Street,[2] but eventually the New Zealanders and other surviving Allied forces had to be evacuated from the island to Egypt.

[10] Back in North Africa, Hanson was promoted to lieutenant colonel and made the permanent CRE for the 2nd New Zealand Division.

He was active in the African campaigns of 1941-42[2] and was recognised for his efforts in September 1942 with an appointment as an Officer of the Order of the British Empire.

Hanson was largely responsible for the development of the river crossing techniques employed by the New Zealanders as they gradually advanced up Italy.

His ministry, which employed almost 4,500 people, played an important role in the economic resurrection of New Zealand following the Second World War, with several major developments relating to hydroelectric schemes.