The 1794 Treason Trials, arranged by the administration of William Pitt, were intended to cripple the British radical movement of the 1790s. Over thirty radicals were initially arrested; three were tried for high treason: Thomas Hardy, John Horne Tooke and John Thelwall. In a repudiation of the government's policies, they were acquitted by three separate juries in November 1794 to great public rejoicing. The treason trials were an extension of the sedition trials of 1792 and 1793 against parliamentary reformers in both England and Scotland.
The historical backdrop to the Treason Trials is complex: it involves not only the British parliamentary reform efforts of the 1770s and 1780s but also the French Revolution. In the 1770s and 1780s, there was an effort among liberal-minded Members of Parliament to reform the British electoral system. A disproportionately small number of electors voted for MPs and many seats were simply bought. Christopher Wyvill and William Pitt argued for additional seats to be added to the House of Commons and the Duke of Richmond and John Cartwright advocated a more radical reform: "the payment of MPs, an end to corruption and patronage in parliamentary elections, annual parliaments (partly to enable the speedy removal of corrupt MPs) and, preeminently and most controversially, universal manhood suffrage." Both efforts failed and the reform movement appeared moribund in the mid-1780s.
Once the revolution in France began to demonstrate the power of popular agitation, the British reform movement was reinvigorated. Much of the vigorous political debate in the 1790s in Britain was sparked by the publication of Edmund Burke's Reflections on the Revolution in France (1790). Surprising his friends and enemies alike, Burke, who had supported the American Revolution, criticized the French Revolution and the British radicals who had welcomed its early stages. While the radicals saw the revolution as analogous to Britain's own Glorious Revolution in 1688, which had restricted the powers of the monarchy, Burke argued that the appropriate historical analogy was the English Civil War (1642–1651) in which Charles I had been executed in 1649. He viewed the French Revolution as the violent overthrow of a legitimate government. In Reflections he argues that citizens do not have the right to revolt against their government, because civilizations, including governments, are the result of social and political consensus. If a culture's traditions were challenged, the result would be endless anarchy. There was an immediate response from the British supporters of the French revolution, most notably Mary Wollstonecraft in her Vindication of the Rights of Men and Thomas Paine in his Rights of Man. In this lively and sometimes vicious pamphlet war, now referred to as the "Revolution Controversy", British political commentators addressed topics ranging from representative government to human rights to the separation of church and state.