William Cavendish (MP for Derby)
William Cavendish MP was an English nobleman and Whig politician. He was the son of Lord George Cavendish, later Earl of Burlington.
He was educated at Eton College, and Trinity College, Cambridge, between 1800 and 1803. He went on a continental Grand Tour in 1803–04, during which he visited Berlin to see the Prussian Army reviews. Although this was during the period of the Napoleonic Wars, his own military service was at home; he was commissioned Captain in the Derbyshire Militia in 1803, was promoted Major in 1804, and was its Colonel from 1811 until his early death.
He was elected MP for Knaresborough in May 1804, then for Aylesbury in July that year. In the next general election in 1806, he was elected for Derby, which he represented until his death.
He married Louisa O'Callaghan, daughter of Cornelius O'Callaghan, 1st Baron Lismore, on 18 July 1807. They had four children, the fourth born after his father's death:
- William Cavendish, 7th Duke of Devonshire
- Lady Fanny Cavendish, married Frederick John Howard and had issue
- Lord George Henry Cavendish
- Lord Richard Cavendish