THISTLEWOOD, ARTHUR (1770-1820), the principal instigator of the Cato Street conspiracy, a plot formed to murder many British ministers in 1820. A son of William Thistlewood, and born at Tupholme in Lincolnshire, young Thistlewood passed his early years in a desultory fashion ; he became a soldier and visited France and America, imbibing republican opinions abroad and running into debt at home. Then taking up his residence in London he joined the Spencean Society, a revolutionary body; associated himself with James Watson (d. 1838) and other agitators; and in December 1816 helped to arrange a meeting in Spa Fields, London, which was to be followed by the seizure of the Tower of London and the Bank of England, and by a general revolution. The proposed rising was a dismal failure, but the Habeas Corpus Act was suspended and Thistlewood and Watson were seized, although upon being tried they were acquitted. Becoming more violent Thistlewood formed other plots, talked of murdering the prince of Wales, and was sentenced to a year's imprisonment for challenging the home secretary, Lord Sidmouth, to a duel. After his release in May 1819, having broken away from Henry Hunt and the more moderate reformers, he prepared a new and comprehensive plot. On the 23rd of February 1820, at a time of great distress and during the unrest caused by the death of George III., the cabinet ministers had arranged to dine at the earl of Harrowby's house in Grosvenor Square. Thistlewood knew of the dinner. With some associates he hired a room in the neighbouring Cato Street, collected arms and made ready to fall upon Harrowby's guests. However the authorities had been informed of the plot, probably by one of the conspirators named George Edwards; officers appeared upon the scene and arrested some of the conspirators; and although Thistlewood escaped in the confusion he was seized on the following day. Tried for high treason, Thistlewood and four others were sentenced to death, and were hanged on the 1st of May 1820.
See Sir S. Walpole, History of England (1890), vol. i.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)