Robertson, Francis (1737/8–1791), soldier and nabob, was probably born at Churchill, parish of Gartan, Co. Donegal, of which his father, the Rev. John Robertson (d. 1756), was the incumbent. His mother's name is not recorded. He had two sisters, of whom the younger, Elizabeth, did not marry. The elder, Sarah, became the second wife of the Rev. Henry Barnard, and mother of Gen. Sir Andrew Francis Barnard (1773–1855), whose memorial of his uncle is in the Grosvenor Chapel, London. It may be surmised that Robertson's education followed the usual course of private teaching by a neighbouring clergyman.
As a cadet in the East India Company's army, he sailed for Calcutta in its ship Success in 1764, was appointed ensign in 1765, and shortly became adjutant to Col. Sir Robert Barker, commanding the 3rd brigade of the Bengal army, stationed at Bankipore. In this appointment Robertson was well placed to maintain communication with officers of two brigades, most of whose captains and subalterns – in protest at the suspension by the Company of the payment of double batta, an allowance intended to maintain their standard of living when in the field – formed an association to surrender their commissions, contending that they were bound only by civil contracts, which could therefore be renounced, on notice given, to take effect on 1 May 1766. Lord Clive declared that this conspiracy was mutiny, punishable by death; but because the legality of such sentences was uncertain, offenders were subjected to various less severe punishments, such as suspension or demotion and, in the grave case of Robertson, who remained defiant, to deportation to England and expulsion from the army. So seriously was his conduct regarded that, despite the restoration of most of the conspirators, an inveterate hostility to him was maintained for several years, reinforced when he returned clandestinely to India in a French ship in 1771, whereupon his immediate expulsion was ordered. Robertson evaded this sanction. Towards the end of 1773 he was restored to the Bengal army in his original rank; one of the letters recommending his reinstatement included the signature of Warren Hastings. Robertson's seniority was reestablished in 1776, after he was described from Calcutta as ‘a man of good character & mild disposition . . .’ and his pointing out in a memorial that he was ‘left the only example of the fatal year 1766, who has not experienced the court's clemency’. He continued to serve till his retirement as a lieutenant-colonel in 1787, when commanding the 6th Bengal European battalion.
He returned to England with a fortune doubtless derived from the subsidies paid by princes whose lands had been invaded by the Rohillas (Pathans) to the company's troops involved in the war to drive them out (1773–4). He died in London 11 September 1791, unmarried, after a long wasting illness contracted in India, having executed a will a year earlier in which he made numerous bequests, including valuable plate to Warren Hastings and a residuary bequest to the diocese of Raphoe of ‘a sum of money which by its interest at the rate of five per cent shall be found sufficient to produce annually to each parish for or towards establishing a school therein, . . . and it is to be understood that such as in said parishes may not be of the established religion are not withstanding to share equally in this legacy . . .’ . Because the amount was not stated, the Irish high court (1803) directed that the sum of £9,300 would be sufficient, plus the accumulation of interest. However, inflation was soon to reduce the bequest's value. In due course the thirty-one schools were gradually absorbed into the national system. Robertson has escaped the notice of historians of education, possibly because he was ahead of his time. The Robertson Charity is still administered by the diocese, under rules formulated by the commissioners of charitable donations and bequests for Ireland. Its early papers are in the PRONI.
Two portraits of Robertson, both in uniform, have been sold at Sotheby's, one (by Carlo Van Loo) by a collateral relative on 16 May 1928; another (by Alexandre Roslin), sold on 10 July 1963, is represented by its photograph in the picture library of the National Portrait Gallery, London. The present whereabouts of both portraits are unknown. An unattributed miniature belongs to a descendant of Sir Andrew Barnard.