Cato Street Conspiracy executions, 19th-century artwork. This group had been plotting to assassinate the British Prime Minister Lord Liverpool, and his cabinet. They were arrested on 23 February 1820 in a struggle during which a policeman was killed. The conspirators were put on trial and convicted of treason. Five of them (Thistlewood, Tidd, Davidson, Ing and Brunt) were hanged and decapitated at Newgate Prison on 1 May 1820. Artwork from 'An Authentic History of the Cato-Street Conspiracy' (Wilkinson, 1820).