On 16th August 1819 around 60,000 people gathered at St. Peter’s Fields, Manchester, to rally for parliamentary reform. Shortly after the meeting began, a troop of Hussars and local yeomanry rode into the crowd, wielding clubs, swords and sabres, leaving 18 dead and more than 700 severely injured. In the following years, the Peterloo Massacre was the subject of several trials and inquiries. It now counts as one of the most significant events in the history of the British labour movement. Francis Archibald Bruton’s account of the day’s events, published for its centenary and based on a detailed examination of contemporary accounts, is both dispassionate and moving.