Dominic Jacotin Gamble is said to have been born on 15 August 1823. His parents' names are unknown, as are the details of his birthplace. It is not known whether he married or had children. He was commissioned as an ensign in the 4th Foot Regiment in 1844. He served with this regiment in the Crimea during 1855, and in 1856 was decorated and promoted to the rank of major.
In 1861, after a period of attendance at the British Army's recently established staff college, Gamble was promoted to lieutenant colonel and took up the post of deputy quartermaster-general on the staff of Lieutenant General Duncan Cameron in New Zealand. Gamble had overall responsibility for the transport, movement and quartering of troops. He was also responsible, in conjunction with the commissariat department, for arranging supplies for the British forces in New Zealand. In addition, Gamble acted as an unofficial chief of staff for Cameron and, later, for Major General Trevor Chute, performing a wide range of tasks and acting as the central point for the receipt of reports for the general officer commanding and for the dispatch of his orders to subordinates.
During 1862 and early 1863 Gamble played a major part in preparations for an invasion of Waikato, setting up camps for troops in South Auckland and organising the construction of the Great South Road. He and members of his staff reconnoitred the land near the Waikato River and established a military telegraph line between Auckland and Pokeno. The military telegraph, the first established in the North Island, was progressively extended until it reached Te Awamutu and Cambridge. Cameron praised the way Gamble oversaw the construction and operation of the telegraph, which proved very useful during the Waikato campaign. It appears that Gamble was involved in the establishment and later expansion of the Commissariat Transport Corps. This unit, originally established in 1861 to supply the troops working on the Great South Road, was essential to the logistics of the Waikato campaign.
In May 1863 Cameron and the rest of his headquarters staff went to Taranaki after the resumption of hostilities there. Gamble worked closely with Cameron, accompanying him when he reconnoitred enemy positions; he also visited British outposts. After Cameron had decided to attack the Maori position at Katikara, Gamble carefully organised the movement of troops and equipment needed for the operation, measures which contributed significantly to the successful outcome of the attack on 4 June 1863.
Late in June 1863 Cameron ordered his staff to return to Auckland, and on 12 July he led his forces into Waikato. Gamble took part in all the campaign's major actions, making an especially valuable contribution during the battle of Koheroa on 17 July.
However, Gamble's most significant role in the campaign was in the field of logistics. Supplying the nearly 10,000 British troops involved in the invasion of Waikato was a major undertaking, which necessitated overcoming not only problems connected with the terrain, but also the threat posed by enemy action. Before the campaign began Gamble made careful preparations and during the operations of 1863–64 took great pains to ensure the efficient functioning of the supply system. He acted decisively and effectively when the flow of supplies to the army was threatened by Maori attacks on traffic along the Great South Road, and when the gunboat Koheroa ran aground. In recognition of his services during the campaign he was created CB in 1864 and awarded the rank of brevet colonel.
In April 1864 Gamble served in the Tauranga campaign, and was present at the British defeat at Gate Pa. Early in the following year he was promoted to colonel and was active in dealing with the logistic problems encountered during Cameron's Wanganui campaign. Gamble continued as deputy quartermaster-general after Chute replaced Cameron in September 1865, and in the early months of 1866 took part in Chute's campaign in South Taranaki and in the march through the bush inland of Mt Taranaki to New Plymouth.
Gamble remained in New Zealand until 1867, when he returned to the United Kingdom. He served as assistant quartermaster-general at Aldershot from 1869 to 1874, was promoted to major general in 1877, and was in command of British forces in the West Indies from 1878 to 1883. In 1887 he was appointed director general of military education. He died at South Kensington, London, on 21 November 1887.
Gamble's contribution to the success of British operations in New Zealand during the mid 1860s is difficult to determine because he worked so closely with Cameron and Chute. His capable handling of logistical problems enabled the British army to make effective use of its manpower and material resources. At the conclusion of the Waikato campaign Cameron praised Gamble, stating that the successful outcome of the operations was in large part due to 'his ability, zeal, and unceasing attention to his important duties'. Gamble demonstrated he also had the ability to lead men in the field. He was a highly intelligent man with a good sense of humour, who seems to have been generally well liked and respected.