The Peterloo Massacre of August 1819 is arguably the single most significant event in the history of Manchester. It continued to resonate nationally throughout the nineteenth century, as a rallying cry for radicals, and a warning to conservatives of the dangers of unbridled democracy and 'mob rule'. Its origins have been sought in the population explosion that Manchester witnessed in the decades after 1790; the lack of democracy, both national and locally (Manchester was still being run by the parish vestry); the dreadful living conditions of the poor; the economic depression that followed the Napoleonic Wars; and the high price of food caused by the Corn Laws.
A vast crowd, drawn from the poor and working classes of Manchester and the surrounding towns, gathered in St Peter's Field on 16 August to hear the radical politician Henry 'Orator' Hunt address a meeting to call for parliamentary reform and the abolition of the Corn Laws. The throng was around 80,000-strong, according to modern estimates, and it included many women and children. The local magistrates had several days earlier declared the meeting illegal, and they mobilized the auxiliary Manchester Yeomanry Cavalry, who were supported by regular troops. As the first speaker began to address the meeting, the order was given for the special constables and cavalry to clear the Field. They succeeded, but at the cost of eleven dead and some 400 injured. Many were trampled or slashed with sabres. The event was quickly christened the Peterloo Massacre, an ironic echo of the Battle of Waterloo four years earlier.
The Government reacted to Peterloo with a series of draconian measures designed to restrict large gatherings and suppress radicalism, but the event and the repression that ensued were a major factor in promoting political and social reform in Britain. A Relief Fund was established after Peterloo, supported by voluntary subscriptions, to provide financial assistance to those who were injured and the families of the dead.