Peterloo is an epic portrayal of the events surrounding the infamous 1819 Peterloo Massacre, in which a peaceful pro-democracy rally at St Peter's Field in Manchester turned into one of the bloodiest, most notorious episodes in British history.
The massacre saw British government forces charge into a crowd of over 60,000 that had gathered to demand political reform and protest against rising levels of poverty. Many protesters were killed and hundreds more injured, sparking a nationwide outcry, but also further government suppression.
The Peterloo Massacre was a defining moment in British democracy that also played a significant role in the founding of "The Guardian" newspaper.