Walter Montagu Douglas Scott, 5th Duke of Buccleuch

Buccleuch was born at Dalkeith House, Midlothian, Scotland, the fifth child of seven, and second son of Charles Montagu-Scott, 4th Duke of Buccleuch, and the Honourable Harriet Katherine Townshend, daughter of Thomas Townshend, 1st Viscount Sydney and Elizabeth Powys. When his older brother, George Henry, died at the age of 10 from measles, Walter became heir apparent to the Dukedoms of Buccleuch and Queensberry. He was only thirteen when he succeeded his father to the Dukedoms of Buccleuch and Queensberry in 1819. Through his grandmother, the 3rd Duchess, he also inherited the ancient northern English lordship of Bowland at this time. However, on his grandmother's death in 1827, the 5th Duke entailed the title upon his uncle, Henry James Montagu-Scott, 2nd Baron Montagu of Boughton. He was educated at Eton and St John's College, Cambridge (M.A., 1827). In June 1833 he was elected a Fellow of the Royal Society.

Statue of Walter Francis Montagu Douglas Scott, 5th Duke of Buccleuch, 7th Duke of Queensberry on the Parliament Square in Edinburgh

A great Scottish land magnate, Buccleuch was a Conservative in politics, and was appointed a Knight of the Garter in 1835 and a Privy Counsellor in 1842. He served as Lord Privy Seal from 1842 to 1846 and as Lord President of the Council from January to July 1846 in Peel's government, when he reluctantly supported Peel's decision to repeal the Corn Laws. After Peel's fall, the Duke's political career largely came to an end. In 1878 he became Chancellor of the University of Glasgow, a post he held until his death in 1884.

He joined the Canterbury Association on 20 May 1848. It was planned to build a town called Buccleuch in his honour near Alford Forest, but this did not eventuate.

Buccleuch married Lady Charlotte Anne Thynne, daughter of Thomas Thynne, 2nd Marquess of Bath and the Honourable Isabella Elizabeth Byng, on 13 August 1829 at St George's church, Hanover Square, London. The couple had four sons and three daughters:

• William Henry Walter Montagu Douglas Scott, 6th Duke of Buccleuch (born 9 September 1831, died 5 November 1914)
• Lord Henry John Montagu Douglas Scott Montagu, 1st Baron Montagu of Beaulieu (born 5 November 1832, died 4 November 1905)
• Lord Walter Charles Montagu Douglas Scott (born 2 March 1834, died 3 March 1895)
• Admiral Lord Charles Thomas Montagu Douglas Scott (born 20 October 1839, died 21 August 1911)
• Lady Victoria Alexandrina Montagu Douglas Scott (born 20 November 1844, died 19 June 1938)
• Lady Margaret Elizabeth Montagu Douglas Scott (born 10 October 1846, died 5 February 1918)
• Lady Mary Charlotte Montagu Douglas Scott (born 6 August 1851, died 13 December 1908)

King George IV spent some days in 1822 as the Duke's guest at Dalkeith Palace, the first visit of a reigning Hanoverian monarch to Scotland. Twenty years later, Queen Victoria also honoured him with a visit. The family continued to hold a high profile in royal circles, being invited to the Coronations of William IV and Victoria, with the Duke acting as Gold Stick.

Buccleuch died in Bowhill, Selkirkshire, in April 1884, aged 77, and was succeeded by his eldest son, William. He was buried in the family crypt of the Buccleuch Memorial Chapel in St. Mary's Episcopal Church, Dalkeith, Midlothian. The church is located on Dalkeith's High Street, at the entrance to Dalkeith Country Park.