James Hadfield (1771/2–1841), suffering from the delusion that the Second Coming of Christ would be precipitated if he were killed by the British government, fired a shot at the King’s Box at Drury Lane theatre. Charges of high treason were dismissed due to a combination of Thomas Erskine’s defence and clear evidence of head trauma sustained during the Battle of Roubaix in 1794. Hadfield was detained for the rest of his life in Bethlehem Hospital.

See The Times, 16 May 1800 and DNB.