Cato Street conspiracy. A plot to murder Lord Liverpool's cabinet at dinner at Lord Harrowby's house in February 1820 was led by Arthur Thistlewood, a former army officer and a follower of the agrarian communist Thomas Spence. It was the culmination of a series of conspiracies to overthrow the government and achieve democratic reform in the period after 1816. The plotters were betrayed by a government spy and arrested as they assembled in a stable in Cato Street. Thistlewood and four fellow-conspirators were executed on May Day, 1820.

E. A. Smith

Cato Street Conspiracy a plot by a group of conspirators led by Arthur Thistlewood (1770–1820) to assassinate participants at a cabinet dinner given by Lord Harrowby in February 1820, as a preliminary to revolution. The attempt failed, and Thistlewood and four of his accomplices were hanged.