Historian and theologian. Born at Borthwick Manse in Midlothian, the son of Rev. William Robertson. He received his education at Dalkeith Grammar School, Married (1751) to Mary Nisbet, with whom he had three sons. Ordained minister of Gladsmuir in 1743. Joint minister, with Dr Erskine, of Greyfriars, Edinburgh (1761-1793). Principal of the University of Edinburgh (1762-1793). In 1761 he was appointed royal chaplain, and in 1764 he became the King's Historiographer. Also a Member of The Poker Club.
Robertson wrote some influential historical works in his time, including History of Scotland 1542-1603 (1759), History of Charles V (1769), History of America (1777) and The Knowledge which the Ancients had of India (1791).
In 1768 Robertson published a pamphlet, Memorial relating to the University of Edinburgh arguing for the rebuilding of the University. Nothing much happened until 1789, when the famous architect Robert Adam, a cousin and lifelong friend of Robertson, was appointed architect of the University.1
Boswell met Dr Robertson at Dempster's in London on July 2, 1763, and they saw a bit of each other for the next month. They probably knew each other in advance, although they don't seem to have talked much before. Boswell mentions Robertson observing that he [Boswell] was "a pleasant man".
Years later, in 1773, Robertson was one of those illustrious Scots whom Boswell asked to invite Dr. Johnson in order to attract him to visit Scotland. Boswell wrote to Robertson:
Our friend Mr. Samuel Johnson is in great health and spirits, and, I do think, has a serious resolution to visit Scotland this year. The more attraction, however, the better; and therefore, though I know he will be happy to meet you there, it will forward the scheme if, in your answer to this, you express yourself concerning it with that power of which you are so happily possessed, and which may be so directed as to operate strongly upon him.1
Robertson replied in the positive, writing
When I saw you last, you gave us some hopes that you might prevail with Mr. Johnson to make out that excursion to Scotland with the expectation of which we have long flattered ourselves. [...] He sometimes cracks his jokes upon us [Scots], but he will find that we can distinguish between the stabs of malevolence and the rebukes of the righteous, which are like excellent oil, and break not the head. Offer my best compliments to him, and assure him that I shall be happy to have the satisfaction of seeing him under my roof.2
Dr Johnson arrived in Edinburgh on August 14, 1773, and he lodged with Boswell. In the afternoon of August 15, Boswell received a note from Robertson stating that "I have been expecting every day to hear from you of Dr. Johnson's arrival. [...] I long to take him by the hand. [...].". Boswell sent back a reply, and Robertson "came and drank wine with us. And then began some animated dialogue", the details of which are described in Journal of a Tour to the Hebrides. Robertson arrived for breakfast again on the next morning, and he accompanied Boswell and Johnson around Edinburgh, visiting such places as Parliament House, the Advocates' Library, St. Giles' Church and the Royal Infirmary. Eventually, they reached Abbey of Holyroodhouse, where Boswell "was much entertained while Principal Robertson fluently harangued to Dr Johnson upon the spot concerning scenes of his celebrated History of Scotland."
Some of William Robertson's writings are still available via the AbeBooks used books search engine, including History of the Reign of Charles the Fifth. His works were occasionally reprinted well into the 19th century, and in 1821(at least) a ten-volume Works of William Robertson, D.D. were released, which is also sometimes available, as are later 6 and 8 volume editions. In 1801(?) a biography of Robertson was written by Dugald Stewart, titled Account of the Life and Writings of William Robertson, which can also occasionally be found. When searching for Robertson it is wise to include the D.D. or DD in some form, to distinguish him from numerous other William Robertsons.
Dr. Robertson and his cousin Robert Adam belonged to the same social circles, and a great account of Adam and the people and society they both belonged to can be found in John Fleming's (1962) Robert Adam and his Circle: In Edinburgh & Rome.