Dictionary of National Biography, 1885-1900/Hay, John (d.1762)
HAY, JOHN, fourth Marquis of Tweeddale (d. 1762), was eldest son of Charles, third marquis, studied law in Edinburgh, succeeded as fourth marquis in 1715, and was on 7 March 1721 appointed an extraordinary lord of session. In 1722 he was chosen one of the sixteen representative peers for Scotland, and was re-elected in 1727. He attached himself to Lord Carteret, and was not re-elected either in 1737 or 1741, but was returned in 1742, and again in 1747, 1752, and 1761. On the resignation of Sir Robert Walpole in February 1742 he joined Lord Wilmington's administration as principal secretary of state for Scotland. He resigned the office in January 1746, when it was abolished. With his death the office of extraordinary lord of session also came to an end. He was for some time principal keeper of his majesty's signet. In 1761 he was appointed lord justice-general, and was in the same year made a governor of the Bank of Scotland. He died in London on 9 Sept. 1762, and in accordance with directions given in his will was privately buried at Yester in East Lothian. By him the estate of Yester was greatly improved, particularly in the way of enclosing fields and planting trees, and towards the close of the eighteenth century the estate contained some of the finest timber in Scotland. He married, 24 May 1748, Lady Frances, daughter of John Carteret, earl Granville, and they had a family of two sons and four daughters.
[Scots Magazine; First Statistical Account of Scotland, 1715; Register of Sasines in General Register House, Edinburgh.]