Crichton-Stuart family, Marquesses of Bute

John Stuart, a son of Robert II of Scotland, was created hereditary sheriff of Buteshire (the islands of Bute, Arran and Cumbrae) in c.1385. The 1st Earl of Bute, so created in 1703, married in 1680 Agnes, daughter of Sir George Mackenzie of Rosehaugh (Ross and Cromarty), but following the death of the 2nd Earl in 1723 the Mackenzie estates passed to a younger son, James Stuart, later Stuart-Mackenzie (d. 1800). The 3rd Earl of Bute (1713-92, Prime Minister 1762-63) married in 1736 Mary Wortley-Montagu (d. 1794), heiress of estates in Yorkshire and Cornwall. These estates, however, passed to their second son James Archibald Stuart-Wortley (1747-1818), who also inherited the Mackenzie estates from his uncle and took the additional name of Mackenzie in 1803. The 3rd Earl acquired the Luton Hoo (Bedfordshire) estate in 1763, but it was sold in 1844.

In 1766 John Stuart, later 4th Earl and (1796) 1st Marquess of Bute, married Charlotte, daughter and heir of the 2nd Viscount Windsor (d. 1758), through whom descended estates and coalfields in South Wales formerly belonging to the Earls of Pembroke (see Herbert, Earls of Pembroke), and the Axwell (Co. Durham) estate of her mother's family of Clavering.

Lord Mount Stuart (d. 1794), son of the 1st Marquess, married in 1792 Elizabeth McDouall-Crichton, daughter of the 6th Earl of Dumfries (d. 1803), bringing estates in Ayrshire and Wigtownshire to the Stuart family. Originally seated at Sanquhar (Dumfriesshire)(later sold), the Crichton family had been established in Ayrshire since the 17th century. William Crichton was created Viscount of Air in 1622 and Earl of Dumfries in 1633. The 3rd Earl (d. 1694) was succeeded by his sister Penelope, who married in 1698 William Dalrymple, second son of the 1st Earl of Stair. On her death in 1742 the Dumfries estates passed to her son as 5th Earl of Dumfries: he also succeeded in 1760 to the earldom of Stair, as 4th Earl, but not to the Stair estates. On the death of the 5th Earl of Dumfries in 1768 the title and estates passed to his nephew Patrick McDouall of Freuch (Wigtownshire).

The 2nd Marquess of Bute (1793-1848) married secondly, in 1845, Sophia Rawdon-Hastings (d. 1859), second daughter of the 1st Marquess of Hastings and Flora Campbell, in her own right Countess of Loudon (d. 1840) (see Rawdon-Hastings, later Abney-Hastings, Marquesses of Hastings and Earls of Loudon), through whom a large quantity of Campbell and Hastings papers passed to the Marquesses of Bute. Sanquhar and Drumlanrig accounts and papers formerly at Drumlanrig (see Montagu-Douglas-Scott, Dukes of Buccleuch and Queensberry) were acquired from a dealer in 1897: the Drumlanrig papers were returned to the 8th Duke of Buccleuch in 1981. In the 20th century the 4th Marquess of Bute added extensively to the manuscript collections at Mount Stuart House and elsewhere.

Estates in 1883: Ayshire 43,734 acres, Buteshire 29,279 acres, Wigtownshire 20,157 acres, Glamorganshire 21,402 acres, Breconshire 59 acres, Monmouthshire 12 acres, Co Durham 1,953 acres, Beds 72 acres, total 116,668 acres worth £151,135 a year, exclusive of Ayrshire minerals worth £2,506.