The Army list or more specifically Army Lists have been kept since at least 1702 a list was published in 1740, annually from 1754 until 1879, then quarterly from 1879 until 1922. As part of The National Archive referenced WO 651754-1879 are printed annual Army Lists. “These official lists give the names of the officers of the several regiments with the dates of their commissions, etc. Lists have been officially posted up with manuscript corrections. For some years the list is in two volumes. In addition to the regular volumes there are special lists of the forces in North America (1783), of British American half-pay officers (1782-1783) and of foreign corps (1794-1802).”
An indication of an officer’s career with some lateral thinking can be readily deduced from an Army List.
With this in mind unable, to suppress the narcissist I looked for a Colclough in 1754 Army list, not one there. Scrolling through my eye was caught by a certain Maitland, left out of the “Additions &t. to the Half Pay, to 20th February 1755” section in the said list. Before exploring Maitland, a note on Half-Pay. It was devised as a retaining fee in the early 18th century, an officer not required in active service was granted this Half-Pay status but could be called up at any time in for instance the Jacobean rebellion of 1715 all were recalled. Latterly in the 19th century it became a way of avoiding service by a convoluted means, wealthy young men could buy a commission to get on the promotion ladder, and the next day go to Half-Pay (signed off by the Crown) and made sure they weren’t called up if the service was in an unpleasant place, but now as a captain they could buy a vacant Major commission in a fashionable regiment go on Half-Pay and onwards and upwards. One day’s ‘full’ service had the same value as many years and entitled the new officer Half-pay status with the associated rank. Anyway Mr. Maitland was not retained or allowed to be retained as he had, in the publication capitals not mine. “PAPIST” written next to his name! Must be story in there…
Taking my fruitless search for a namesake in the 1754 Army List(s) and putting it to one side, here is a more fruitful way of looking in the Army Lists. I would expect you have a name, and what you need ideally is the name of the regiment and some dates.
For example: An ancestor named Robert Shean known to have been an army surgeon in the 1830’s, possibly served with served with the Bedfordshire regiment in 1834. I will look in the army list for 1834 in the National Archives. Find that the Bedfordshire Regiment was known as the 16th (Bedfordshire) regiment of Foot. Then scroll through the names and there is the Surgeon, Robert Shean, appointed to position 26th October 1830. These snippets of information can be used to search for him in 1835 and 1833, possibly the 1841 census, marriage records and onwards…
Building your family tree is teasing the last piece of valuable data from snippets and knowing where to look. I can help.
 National Archives (Great Britain). WO – Records created or inherited by the War Office, Armed Forces, Judge Advocate General, and related bodies. https://discovery.nationalarchives.gov.uk/browse/r/r/C259: accessed 05 March 2021.
 Public Record Office (1982). War Office: printed annual army lists. 1754. The national Archives. Kew, England. Catalogue reference: WO 65/1/1. https://discovery.nationalarchives.gov.uk/ : accessed 05 March 2021.
 Ibid. p. 61.
 Woodham Smith, Cecil Blanche Fitz Gerald (1958). The reason why : a behind the scenes account of the charge of the Light Brigade. P. 31. Harmondsworth : Penguin. www.thearchive.org : accessed 05 March 2021.
 Public Record Office (1982). War Office: printed annual army lists. 1754. The national Archives. Kew, England. Catalogue reference: WO 65/1/1. P. 61. https://discovery.nationalarchives.gov.uk/ : accessed 05 March 2021.