1st Earl of Devonshire

William was the second and favorite son of Sir William Cavendish and his third wife, Bess of Hardwick, grandson of Thomas Cavendish and Alice Smith, John Hardwick and Elizabeth Leeke.

William married Anne Kighley, the daughter of Henry Kighley of Keighley, Yorkshire. They married about 21 March 1580, and had three sons and three daughters including:
* William Cavendish, 2nd Earl of Devonshire
* Frances, wife of Sir Henry Pierrepoint
* Gilbert, died young
* James, died in infancy

Secondly, her married Elizabeth, the daughter of Edward Boughton of Couston, and the widow of Sir Richard Wortley. They had one son, Sir John, Knight of the Bath, who died in 1618.

William was educated with the children of George Talbot, 6th Earl of Shrewsbury, whom his mother married after his father's death. Following his hefty allowance during his youth, his inheritance included a vast fortune and four important houses; Worksop, Oldcotes, Chatsworth and Hardwick Hall. William invested extensively in America and Bermuda, and a supporter of colonizing Virginia. The Devonshire colony in Bermuda was named after him.

He was in attendance on James I in a progress in Wiltshire in 1618, and on 2 August was created Earl of Devonshire, while the court was staying at the Bishop of Salisbury's palace; he was reported to have paid £10,000 for the title. He died on 3 March 1626, and was buried at Edensor.

1st Earl of Devonshire

William was the second and favorite son of Sir William Cavendish and his third wife, Bess of Hardwick, grandson of Thomas Cavendish and Alice Smith, John Hardwick and Elizabeth Leeke.

William married Anne Kighley, the daughter of Henry Kighley of Keighley, Yorkshire. They married about 21 March 1580, and had three sons and three daughters including:
* William Cavendish, 2nd Earl of Devonshire
* Frances, wife of Sir Henry Pierrepoint
* Gilbert, died young
* James, died in infancy

Secondly, her married Elizabeth, the daughter of Edward Boughton of Couston, and the widow of Sir Richard Wortley. They had one son, Sir John, Knight of the Bath, who died in 1618.

William was educated with the children of George Talbot, 6th Earl of Shrewsbury, whom his mother married after his father's death. Following his hefty allowance during his youth, his inheritance included a vast fortune and four important houses; Worksop, Oldcotes, Chatsworth and Hardwick Hall. William invested extensively in America and Bermuda, and a supporter of colonizing Virginia. The Devonshire colony in Bermuda was named after him.

He was in attendance on James I in a progress in Wiltshire in 1618, and on 2 August was created Earl of Devonshire, while the court was staying at the Bishop of Salisbury's palace; he was reported to have paid £10,000 for the title. He died on 3 March 1626, and was buried at Edensor.