On 19 September 1920 more than forty IRA volunteers people were arrested on the Dublin Mountains as they drilled and carried out military maneuvers.

Surrounded, the men were fired on by the military and one man, Sean Doyle aged 19 was shot dead when he was hit by a volley of bullets. All prisoners it was reported were to be tried before the courts including their leader, Capt Ryan who was described as a company commander. The arrested men refused to recognize the courts or give their names. It was stated that the men were not in possession of arms or ammunition when they were captured. At the inquest and in several newspaper accounts of the incident, it was claimed that Doyle was not armed and was in the process of surrendering when he was shot. Despite previous warnings, the IRA had decided to go ahead with the training camp but came to rue the decision. However, the controversy over the killing of the unarmed Doyle tuned out to be a huge propaganda coup for the IRA and Sinn Fein. Doyle’s funeral on 23 September was a huge display of republican sentiment in Dublin. Several councils and public bodies passed resolutions of sympathy with his family and rejected the manner in which he was killed. Thousands lined the streets to watch a procession volunteers, Cumann na mBan, Na Fianna Éireann, and members of Dail Eireann including Arthur Griffith.  

Source: Ulster Herald 1901-current, 25.09.1920, page 6

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