[1] When James II mustered an army on Hounslow Heath in 1685, he appointed a certain John Shales as Commissary General of provisions, responsible for sourcing, storing and issuing food for the troops and forage for the horses.
In addition he was to license and regulate sutlers, to procure wagons, carriages, horses and drivers when required for transport and to account for all payments to the Lord High Treasurer and the Paymaster-General of His Majesty's Forces.
Otherwise, in the eighteenth century, arrangements for supply and transport tended to be devolved to individual regiments, who would work with a combination of civilian contractors and other agencies.
Transport (albeit nominally a responsibility of the Stores Branch) was something of a poor relation; this in part led to the Commander-in-chief establishing a separate Royal Waggon Train.
In 1822 the Stores Branch (along with its warehouses and staff both at home and abroad) was transferred to the Board of Ordnance, which also took on responsibility for provision of food, forage and fuel to troops in England ten years later.
[3] Provision of food, forage and fuel for the army abroad remained a (albeit secondary) responsibility of the Commissariat at this time.
In the "Major General's Song" in The Pirates of Penzance by Gilbert and Sullivan, the Major-General boasts that when, among many other bits and pieces of seemingly elementary or irrelevant information, he "know(s) precisely what is meant by commissariat", he will be the best officer the army has ever seen (satirizing 19th century British officers' lack of concrete military knowledge).
In the penal colonies of New South Wales and Van Dieman's Land (now Tasmania), the Commissariat Department also had responsibility for the needs of convicts and, in the early days, provisions sold by storekeepers, as well as for military garrisons and naval victualing.
[4] Similar arrangements applied in the Moreton Bay penal colony (originally part of New South Wales) and Western Australia.