On 18 September 1867 a group of armed Irishmen freed two Fenian prisoners from a prison van on Hyde Road, Manchester. During the raid a policeman, Sergeant Charles Brett, was accidentally shot dead. Three Irishmen, William Allen, Michael Larkin and Michael O'Brien, were convicted for the shooting and hanged in public outside the New Bailey prison, Salford on 23 November 1867.
Few believed that they were guilty, and major demonstrations were held in protest in England, Ireland and the United States. The executions served as a spur to those seeking Irish independence. Frederick Engels was living in Manchester at this time with an Irishwoman, Lizzie Burns. After the execution he noted prophetically that the executions had "accomplished the final act of separation between England and Ireland. The only thing the Fenians still lacked were martyrs. They have been provided with these".