William Cavendish, 6th Duke Of Devonshire

William George Spencer Cavendish, 6th Duke of Devonshire (21 May 1790 – 18 January 1858), was an English peer, courtier, and politician associated with the Whig party. He was born in Paris, France, the son of William Cavendish, 5th Duke of Devonshire, and Lady Georgiana Spencer, daughter of John Spencer, 1st Earl Spencer. His education included attendance at Harrow School and Trinity College, Cambridge.

Devonshire was styled Marquess of Hartington until 1811 when he succeeded to the dukedom following the death of his father. At that time, he inherited several significant estates, including eight stately homes and approximately 200,000 acres of land. Both his mother and father died during his youth; Lady Georgiana passed away in 1806, and William inherited the title and family holdings upon his father's death in 1811, at the age of 21.

In his political career, Devonshire followed the Whig family tradition. He was a supporter of Catholic emancipation, the abolition of slavery, and the reduction of factory working hours. He served as Lord Chamberlain of the Household during two periods, from 1827 to 1828 under Prime Minister George Canning and Lord Goderich, and from 1830 to 1834 under Lord Grey and Lord Melbourne. In 1827, he was sworn into the Privy Council and was made a Knight of the Garter. He was appointed Ambassador Extraordinary to the Russian Empire at the coronation of Tsar Nicholas I in 1826. Additionally, he served as Lord Lieutenant of Derbyshire from 1811 until his death in 1858 and carried the globus cruciger during King George IV's coronation.

Devonshire's early-onset deafness limited his participation in public life; however, he maintained various interests and held notable positions. His interest in gardening and horticulture was significant, and he dedicated considerable effort to the development of his estates. Among his projects was the rebuilding of the village of Edensor and improvements to his stately homes and gardens. He was a friend of Sir Joseph Paxton, whom he appointed as head gardener at Chatsworth House in 1826. Paxton expanded the gardens extensively, including the construction of a substantial conservatory that served as a model for The Crystal Palace in London.

In 1838, Devonshire was elected President of the Royal Horticultural Society, a position he held until his death in 1858. His horticultural interests also led to his role in establishing the Royal Botanic Gardens at Kew as a national botanic garden. The Cavendish banana, the most commercially exploited banana variety globally, is named after him. He acquired an early specimen and raised it in his greenhouse; this plant is the progenitor of nearly all Cavendish bananas existing today.

Devonshire was also a patron of the Derby Town and County Museum and Natural History Society and played a part in founding the Derby Museum and Art Gallery in 1836. He traveled extensively and authored a privately printed book in 1845 titled "Handbook to Chatsworth and Hardwick," detailing the history of his family’s principal estates. The book received praise from the author Charles Dickens.

In his personal life, Devonshire was a close friend of the Prince Regent and maintained friendships with figures such as Antonio Canova and Charles Dickens. Much of his private correspondence, including letters to his mistresses, was destroyed by Victorian relatives. He considered marrying Lady Caroline Ponsonby, his cousin, but she married William Lamb instead. Devonshire died at Hardwick Hall in Derbyshire in January 1858 at the age of 67. He left an estate valued at £500,000. As he was unmarried, the dukedom was inherited by his cousin William Cavendish, 2nd Earl of Burlington. His junior title of Baron Clifford fell into abeyance between his sisters, Georgiana, Countess of Carlisle, and Harriet, Countess Granville.