Arthur Thistlewood (bap. 1774, d. 1820), ultra-radical Spencean leader, plotted to assassinate the cabinet as they dined at the home of the earl of Harrowby on 23 February. However, the advertisement that had led Thistlewood and the other conspirators there was a hoax and they were met in a Cato Street loft by Bow Street Runners and guards. Thistlewood killed a police officer, Richard Smithes, with a rapier and escaped but was apprehended the following morning. Convicted of high treason Thistlewood and four others were hanged, publicly decapitated and buried at Newgate on 1 May while five others were transported.

See DNB.