Dictionary of National Biography, 1885-1900/Beauclerk, Topham
BEAUCLERK, TOPHAM (1739–1780), a friend of Dr. Johnson, was the only son of Lord Sydney Beauclerk and a grandson of the first Duke of St. Albans. He was born in December 1739, and on the death of his father, 23 Nov. 1744, succeeded to the estates which Lord Sydney Beauclerk, a man notorious in his day for fortune-hunting, had inherited from Mr. Richard Topham, M.P. for Windsor. Topham Beauclerk matriculated at Trinity College, Oxford, 11 November 1767, but does not seem to have taken any degree.
Whilst there he had the good fortune to make the acquaintance of Bennet Langton. Beauclerk's tastes were widespread, both in science and literature; his conversation was easy and vivacious, with that 'air of the world' which showed that he had seen much, and knew how to describe what he had seen. But his talents would have passed away without leaving any record behind them had he not sought the acquaintance of Dr. Johnson, and been loved by him with signal devotion. From 1767 to 1780 his name and his good qualities are written in the pages of Boswell. He married, at St. George's, Hanover Square, 12 March 1768, Lady Diana Spencer, eldest daughter of the second Duke of Marlborough, two days after she had been divorced from Lord St. John and Bolingbroke, and she made an excellent wife to her new husband. Beauclerk died at Great Russell Street, Bloomsbury, 11 March 1780, leaving issue one son and two daughters. His library of 30,000 volumes, housed, as Horace Walpole remarks, in a building 'that reaches half-way to Highgate,' was sold by auction April-June 1781, and was especially rich in English plays and English history, travels and science. A catalogue ('Bibliotheca Beauclerkiana') is in the British Museum. Many of Beauclerk's letters are in the possession of Lord Charlemont.
[Brydges's Collins's Peerage, i. 249; Gent Mag. 1. 155 (1780); Hardy's Lord Charlemont; Cornhill Mag. xxx. 281-96 (1875), by G. B. H. (Hill).]