For family tree see Watsons on Ancestry (subscription required)
James Watson (d1808) of Crantit, Orkney, was factor for the estates of Lord Dundas. He married Christian Robertson (1780-1842) whose family (Robertsons of Kiltearn) had many connections with Demerara. Four of the couple's five sons - Harry (Henry) Robertson Watson (1801-36), Andrew Watson (1803-37), William Robertson Watson (1807-76) and Peter Miller Watson (1805-69) - went out the Demerara, where the two older brothers died. The fifth brother, James [b1809], became a lawyer in London.
Peter, Harry and Andrew all received compensation on emancipation of their slaves in 1834: Peter for sixteen, Harry for seven, and Andrew for six. [UCL: Legacies of British Slave Ownership]
Peter Miller Watson had an illegitimate son, Andrew [1856-1921], and an illegitimate daughter, Annette, in Guyana, whose mother was called Hannah (or Anna) Rose [Information from Andrew's marriage certificate, 1877: 644/13 0100; and from Peter's will]. Andrew was educated in England and then attended Glasgow University, where he studied engineering. He is widely considered to be the world's first black association footballer to play at international level and was capped three times for Scotland between 1881 and 1882.
Andrew Watson (top centre) with the Scottish team that played England at Hampden Park on the 11 March 1882.
Thanks to John Platt and Bob Bruce for other information on this page and for establishing the connection between Andrew Watson and both Orkney and the Robertson family.