Background
Watson-Wentworth was the only son and heir of Honorary Thomas Watson (later Watson-Wentworth, the third son of Edward Watson, 2nd Baron Rockingham) and his wife, Alice, a daughter of Sir Thomas Proby, 1st Baronet.
Watson-Wentworth was the only son and heir of Honorary Thomas Watson (later Watson-Wentworth, the third son of Edward Watson, 2nd Baron Rockingham) and his wife, Alice, a daughter of Sir Thomas Proby, 1st Baronet.
He was educated at Street John's College, Cambridge (1707).
In 1708 he bought Hallfield House, near Sheffield, and succeeded his father in 1723. In 1725, he was appointed a Knight of the Bath, admitted to the Privy Council of Ireland in 1733, and was Lord Lieutenant of the West Riding of Yorkshire from 1733 to 1750. In 1728, he was created Baron Malton.
At this time he deliberately burned most of the manuscripts left by the 17th-century antiquary Richard Gascoigne.
This act has been attributed to legal advice from his attorney. In 1734, he was created Earl of Malton, and in 1746, Marquess of Rockingham.
They had five children:
William, styled Viscount Higham (1728–1739)
Honorary Charles, later styled Viscount Higham, later still 2nd Marquess of Rockingham (1730–1782), Prime Minister of Great Britain.
Lady Anne (d 1769), married William FitzWilliam, 3rd Earl FitzWilliam.
Lady Mary, married John Milbanke. Lady Henrietta Alicia, married William Sturgeon.
6th Parliament of Great Britain. 7th Parliament of Great Britain. 5th Parliament of Great Britain]
From 1715 to 1727, Watson-Wentworth was Member of Parliament for Malton, and for Yorkshire from 1727 to 1728.