By the end of the war, he had advanced in rank to brigadier general, commanding a number of brigades in the New Zealand Division.

[1] In 1900, Hart's brother Walter travelled to South Africa for service with the Fourth Contingent in the Second Boer War.

[1] It was common practice in the Volunteer Force for the men of a unit to elect their officers although they were sometimes directed by their superiors to vote for certain candidates.

The battalion embarked from Wellington in October 1914 for Egypt,[3] and upon arrival, was primarily engaged in training before it was deployed along the Suez Canal late in January 1915 to support Indian troops stationed to guard against a rumoured Turkish attack.

[4] At this stage of the war, the Allied forces were preparing for the Gallipoli Campaign, which was part of a plan conceived by the First Lord of the Admiralty, Winston Churchill, to seize control of the Dardanelles.

He returned to the Dardanelles in September 1915 as commander of the Wellington Battalion, Malone having been killed in action in early August during the Battle of Chunuk Bair.

[15] Hart led his battalion during the Battle of Flers-Courcelette and the subsequent period in the trenches,[16] and was mentioned in despatches for his work during this time.

[19] The brigade was in reserve for the subsequent First Battle of Passchendaele, and, apart from a brief period in training, would remain in the Ypres sector until January.

[22] Upon recovery from the effects of his gassing, and aided by the temporary presence of his wife Minnie, Hart returned to England and was placed in command of the New Zealand reserves at Sling Camp in Bulford.

[8] Hart's duties at Sling Camp ended in July, when he was recalled to France to take over command of the 3rd New Zealand (Rifle) Brigade.

[8] He led the brigade through the Hundred Days Offensive, which included an action during the Second Battle of Bapaume that impressed his commanding officer, Russell.

[25] After the armistice that ended the war, Hart led the brigade into Germany for occupation duties with the remainder of the New Zealand Division.

[26] The division itself was in the process of demobilising, with around 1,000 men returning to New Zealand via England every week, and the Rifle Brigade was disbanded in early February.

[26] Hart arrived in his home town of Carterton to a hero's welcome on 25 April 1919, five years to the day after being landed at Gallipoli.

The guest of honour at several receptions held around the Wairarapa over the next several days, he made a point of acknowledging the role played by the ordinary soldier in the eventual victory over the Germans while downplaying his own contributions.

His services in the war were subsequently recognised with his appointment as a Companion of the Order of the Bath in the 1919 King's Birthday Honours.

[29] He maintained an association with the military; after an initial spell in the reserve of officers, he resumed his involvement with the Territorial Force and served as commander of the 2nd (Wellington) Infantry Brigade for several years.

[28] In 1930, Hart applied for and was appointed to the position of Administrator of Western Samoa, which was controlled by New Zealand under a mandate from the League of Nations.

The Mau movement in particular was agitating for self-determination and employed tactics of civil disobedience as a means of opposing the New Zealand administration.

[32] Although his new position of Deputy Controller of the Eastern District was nominally based in Jerusalem, he and his wife initially moved to Cairo because of the Arab revolt against the British Mandate in Palestine.

[32] Hart's new role involved overseeing the upkeep of the cemeteries and memorials established by the Commission in the Middle East, Turkey and Greece.

Ensuring the maintenance of these places required extensive travel, and his duties also became more difficult when Italy joined in the Second World War in June 1940 and conflict broke out in the Middle East.

Consequently, Hart became Assistant Director, Graves Registration and Inquiry Section for the Middle East, in addition to his existing Commission duties.

Early the following year Hart visited the El Alamein battlefield and the nearby cemetery, the establishment of which was partly due to the infrastructure he helped put in place, to lay flowers at his nephew's grave.

In speeches that he made during his community and RSA duties, he continued to advocate the importance of the war in countering Imperial German aggression.

[28] In 1955, in honour of the 40th anniversary of the formation of the Rifle Brigade, Hart presented the flag which he had been given by the mayor of Le Quesnoy following its capture from the Germans in 1918 to Wellington Cathedral.

[34] With age, Hart's involvement in community affairs decreased but he remained physically active, regularly playing golf and bowls.

He died at his home in Masterton on 5 March 1968, his wife having predeceased him by nearly 18 months, and was buried with full military honours.