His son was Rev William Robertson; b. 30 Jun 1686 of Wemyss, Fife; 3rd son of William Robinson of Gladney + Margaret Mitchell; d. 16 Nov 1745;
So the William who married Margaret Mitchell cannot have been the son of William Robertson of Muirton, 4th of Muirton & Isabel Petrie
I am disconnecting and adjusting profile dates.
Tagging Private User & Angus Wood-Salomon & Private User who brought to attention.