CAVENDISH, William, Duke of New castle, English general: b. 1592; d. 25 Dec. 1676. James I made him knight of the Bath in 1610 and in 1620 raised him to the peerage as Viscount Mansfield. In 1628 he became Earl of Newcastle by Charles I and later became the tutor of Charles' son, afterwards Charles II. On the approach of hostilities between the Crown and Parliament he embraced the royal cause and was invested with a commission constituting him general of all His Majesty's forces raised north of the Trent, with very ample powers. Through great exertions, and the expenditure of large sums from his private fortune, he levied a considerable army with which, for some time he maintained the King's cause in the north. In military matters he de pended chiefly on his principal officers, it is said, but the numerous successes obtained by him render this unlikely. In 1634 he obtained a complete victory over Lord Fairfax on Ad walton Moor, and recovered all Yorkshire except Hull; but next year on the arrival of the Scottish army and its junction with the Par liamentary forces, threw himself into York.
Having been relieved by Prince Rupert, he was present at the battle of Marston Moor next day, after which he left the kingdom. His term of exile was chiefly spent in Antwerp, where he was for a long time so straitened in circumstances that he had on one occasion to pawn his wife's jewels. He returned after an absence of 18 years, and was rewarded for his services and sufferings with the dignity of Duke of Newcastle. His works include 'La methode et invention nouvelle de dresser les chevaux) (Antwerp 1657, (A New Method and Ex traordinary Invention to Dress Horses and Work Them According to Nature) (1667) ; some comedies of no merit, and several worth less poems. Consult 'Life of the Duke of New castle' by Margaret Lucas, his second wife (London 1886). Pepys ridicules this work in his