On 4 February 1795 the Welsh stonemason Edward Williams, better known as Iolo Morganwg (‘Iolo from Glamorgan’), celebrated the acquittals of Thomas Hardy, John Horne Tooke and John Thelwall at the Crown and Anchor Tavern with a song. Trial by Jury, subsequently printed as a broadside, comprises four heady stanzas of ‘Triumph's exulting excess’: mountains of innocence standing firm against the raging storms, spies and informers helplessly gnashing their fangs. In the final stanza, as homage is paid to the defendants’ lawyers, the glorious institution of Trial by Jury is claimed for Britain.

This is not untypical. On the printed page, all brash capital letters, italics and exclamations, Iolo does tend to assert more than he persuades. But a good voice can work magic, even on bombast, and this is, or rather was, a performance. In front of an audience of some 900 people, Iolo Morganwg became at this point most fully, and most publicly, the character for which he was best known in radical and literary circles in 1790s London, ‘Bard Williams’, or, as he put it himself in the rather wittier ‘Newgate Stanzas’, the ‘Bard of Liberty’: