George Vanden Bempde (earlier Johnstone) (29 May 1720 â 29 April 1792), 3rd Marquess of Annandale, succeeded James Johnstone, 2nd Marquess of Annandale on his death in 1730 (but in practice from 1733), and enjoyed that title from then to his own death, whereupon the title became extinct.
His change of surname from Johnstone to Vanden Bempde was a condition of receiving an inheritance from John Vanden Bempde, and was confirmed by a private act of Parliament, (18 Geo. 2. c. 4 ). The philosopher David Hume wrote in his autobiography that he spent a year (1745-46) living with and supporting the "young nobleman", "for the state of his mind and health required it".