PONSONBY, William, Visct. Duncannon (c.1704-93).

Published in The History of Parliament: the House of Commons 1715-1754, ed. R. Sedgwick, 1970
Available from Boydell and Brewer



8 Mar. 1742 - 1754
1754 - Nov. 1756
13 Dec. 1756 - 4 July 1758

Family and Education

b. c.1704, 1st surv. s. of Brabazon, 1st Earl of Bessborough [I], and 1st Baron Ponsonby, by his 1st w. Sarah, da. of James Margetson of Sysonby, Leics., wid. of Hugh Colvill of Newtown, co. Down. educ. Grand Tour. m. 5 July 1739, Lady Caroline Cavendish, da. of William Cavendish, 3rd Duke of Devonshire, 5s. 4da. suc. fa. 4 July 1758.

Offices Held

M.P. [I] 1725-58.

P.C. [I] 19 Nov. 1741; sec. to ld. lt. [I] 1741-4; ld. of Admiralty 1746-56, of Treasury 1756-9; jt. postmaster gen. 1759-1762, 1765-6; P.C. 12 July 1765.


Duncannon was returned for Derby in 1742 on the interest of his father-in-law, the Duke of Devonshire, who secured a seat on the Admiralty board for him in 1746 and an English barony for his father in 1749.1 He died 11 Mar. 1793.

Ref Volumes: 1715-1754

Author: Romney R. Sedgwick


  • 1. Walpole, Mems. Geo. II, i. 196.