David Erskine - Lord Cardross - Earl of Buchan
Son of Henry Erskine (1710-1767), 10th Earl of Buchan, and Agnes Steuart (b. ca. 1715),1
David Erskine was educated at St. Andrews University and Edinburgh University and eventually went on to found the Society of Antiquaries of Scotland in 1780.
In 1767 he was appointed by William Pitt to be secretary to the British ambassador to the court of Madrid. He refused to take up the position, however, on the grounds that the ambassador, Sir James Gray, was of "inferior rank".2
Apart from having commissioned two bridges over the River Tweed, both of which collapsed - the first of them after having been open only for a few months - he is probably best known today for his Essay on the Lives of Fletcher of Saltoun and the Poet Thomson (1792).
Cardross was present when Boswell called on William Pitt in his house in Bond Street on February 23, 1766.