Alfred William Robin, incorrectly registered at birth as Robbin, was born on 12 August 1860 at Riddles Creek, Victoria, Australia. He was the son of James Robin, then working as a baker, and his second wife, Anne McDougall. The family moved to Dunedin, New Zealand, about 1861, and James Robin established what eventually became a thriving coach and carriage building business. Alfred Robin was educated at R. Gardner's Milton Hall school, Stuart Street and, for one year (1873), at the High School of Otago. On leaving school he joined his father's business as an apprentice, and later became a working partner.
From a very early age Robin was fascinated with military affairs. He was battery bombardier in his high school's artillery cadet corps, and between 1878 and 1883 he served with the New Zealand Regiment of Volunteer Artillery, the Southland Hussars and the Dunedin Cavalry Volunteers (as sergeant major). This unit became the Otago Hussars in 1886 and Robin received his commission as a lieutenant on 3 July 1889; he was promoted to captain on 7 February 1891. From 1891 to 1898 he commanded the Hussars; it was regarded as the most efficient volunteer corps and Robin as the 'smartest Commanding Officer in the Colony'.
In early 1897 Robin was appointed to select, train and command the mounted section of the contingent sent to Queen Victoria's diamond jubilee celebrations. In London he was selected to command the colonial section of the bodyguard escorting the Queen on her return to Windsor after Jubilee Day. In 1898 Robin resigned his partnership in the family business. On 7 December 1898 he was promoted to major and given command of the newly formed Otago Battalion of Mounted Rifle Volunteers. He accepted a commission in the New Zealand permanent forces in September 1899 and, as instructor to South Island mounted rifle units, he established a tactical school for officers.
Robin was in command of the First Contingent, which was dispatched to the South African War in October 1899. From May 1900 to April 1901 he commanded the 1st New Zealand Regiment and on 25 June 1900 he was promoted to lieutenant colonel in the New Zealand Militia. Senior British and other colonial officers admired Robin's competence and his ability to inspire loyalty in those under his command. On three occasions he was mentioned in dispatches for his leadership and personal exploits, and he was appointed a CB on 19 April 1901. He became a national celebrity, his portrait being included on commemorative medals, post office stationery and Christmas cards. He returned to New Zealand in May 1901, was presented with illuminated addresses, swords and caskets, and on 14 January 1902 was given a brevet colonelcy.
From 1901 to 1906 Robin was commander of the Otago Militia and Volunteer District. In December 1906 he was appointed to the newly established Council of Defence as chief of the General Staff, the first colonial to hold the country's highest military position. The Council of Defence, feeling that the volunteer system no longer met the country's defence needs, determinedly prodded a reluctant government to introduce some form of compulsion. Robin helped to implement the system of compulsory military training after its eventual introduction in 1909.
In December 1910 Major General A. J. Godley was appointed commandant of the New Zealand Defence Forces and became chief of the General Staff. Robin became adjutant and quartermaster general. He was awarded the Colonial Auxiliary Forces Officers' Decoration in 1911, and appointed a CMG in 1912. In February 1912 he became the New Zealand representative on the Imperial General Staff at the War Office in London.
Robin was present at two Imperial General Staff conferences at which the question of training dominion forces was exhaustively discussed. He closely studied ordnance and administrative services and the movement of troops by land and sea, and prepared a mobilisation scheme for dominion territorial forces.
Robin arrived back in New Zealand in December 1913 and on 13 February 1914 resumed his appointment as quartermaster general. On the outbreak of war in 1914 he offered to serve overseas. The government, however, considered his recent experience invaluable and kept him at home. With the departure of Godley to command the New Zealand Expeditionary Force, Robin was appointed, on 10 September 1914, commandant to the New Zealand military forces within New Zealand. He was promoted to brigadier general on 18 June 1915. In this capacity he organised reinforcements and training for the Expeditionary Force.
Robin was appointed a KCMG in 1916 and on 21 October, on Godley's recommendation, promoted to major general. He ceased to be quartermaster general on 5 May 1919 and relinquished command of the forces on 10 December that year. He declined the offer of an appointment as military representative at the New Zealand High Commission, London. For a short period in 1920 Robin was acting administrator of Western Samoa, and on 1 January 1921 he was posted to the retired list of officers. In recognition of his services during the war the president of the French Republic appointed him a chevalier de la Légion d'honneur in 1922.
In retirement Robin took an active interest in the First New Zealand Mounted Rifles' Association – of which he was president from its foundation in 1901 until 1935 – and the South African War Veterans' Association of New Zealand. For over 10 years he was Wellington metropolitan commissioner of the Boy Scouts' Association and in April 1933 received scouting's highest award, the Silver Wolf. He was a devoted supporter of the St John Ambulance Brigade and was appointed a Knight of Grace of the Order of St John on 17 May 1929.
Alfred Robin never married. He died at his Wellington home on 2 June 1935, having declined a military funeral. Robin was noted for a selfless dedication, an enjoyment in working long hours, and a thorough understanding and knowledge of military affairs. An accomplished artist who had exhibited at the Otago Art Society between 1885 and 1906, he demonstrated his artistic abilities in the quality of his military plans and maps. Five feet 8½ inches tall and strongly built, Robin developed from a handsome young officer to a distinguished general. He was idealistic and patriotic but modest, and immensely proud of having risen from the ranks of the volunteers. His character and his ability earned him both popular acclaim and the warm esteem of politicians and fellow soldiers.