William Crichton, 9th Lord Crichton of Sanquhar later 1st Viscount of Ayr later 1st Earl of Dumfries was created 2 Feb 1622 Lord of Sanquhar and Viscount of Ayr, 12 Jun 1633 Lord Crichton of Sanquhar and Cumnock, Viscount of Ayr and Earl of Dumfries. The Lordship of Crichton of Sanquhar has been held by the Earls of Dumfries (Marquesses of Bute from 16 Nov 1814) since 12 Jun 1633.
According to the Historical gazetteer of London before the Great Fire: Cheapside; parishes of All Hallows Honey Lane, St Martin Pomary, St Mary le Bow, St Mary Colechurch and St Pancras Soper Lane Sir Robert Swift, first husband of Ursula Barnham, died in 1625 and by 1626 Ursula had married William, 7th lord Crichton of Sanquhar, 1st viscount Aire and subsequently (1633) 1st earl of Dumfries. His son William, later 2nd earl of Dumfries, had already married, c. 1618, when both were aged 13 or less, Penelope, daughter of Sir Robert Swift and Ursula Barnham. In 1626 William, lord Aire, and Ursula conveyed 14 messuages and 14 shops in St. Mary Colechurch and St. Mildred parishes by fine to John, earl of Annandale, and James Maxwell, esquire, who were to hold them to the use of William lord Sanquhar the younger.