Igoe Gang

The Cairo Gang was a group of British intelligence agents who were sent to Dublin during the Irish War of Independence to conduct intelligence operations against prominent members of the Irish Republican Army (IRA) – according to Irish intelligence, with the intention of assassinating them. Twelve men including British Army officers, Royal Irish Constabulary officers and a civilian informant, were killed on the morning of 21 November 1920 by the Irish Republican Army in a planned series of simultaneous early-morning strikes engineered by Michael Collins. The events were the first killings of Bloody Sunday.

Some Irish historians (such as Tim Pat Coogan and Conor Cruise O'Brien) dispute assertions of a common history of service in the Middle East as the reason for the unit's nom de guerre. It has been suggested that they received the name because they often held meetings at Cafe Cairo at 59 Grafton Street in Dublin. Earlier books on the 1919–1923 period do not refer to the Cairo Gang by that name.

By 1920, the IRA's Dublin headquarters, under the direction of Michael Collins had effectively eliminated, through targeted assassination and intelligence penetration, the G Division of the Dublin Metropolitan Police, previously the mainstay of the Crown's intelligence operations against Irish Republicans. In response the Dublin Castle administration, the then headquarters of the British government in Ireland were forced to look for external intelligence support.

In January 1920, the British Army Intelligence Centre in Ireland stood up a special plainclothes unit of 18–20 demobilized ex-army officers and some active-duty officers to conduct clandestine operations against the IRA. The officers received training at a school of instruction in London, most likely under the supervision of Special Branch, which had been part of Britain's Directorate of Home Intelligence since February 1919. They may also have received some training from MI5 officers and ex-officers working for Special Branch. Army Centre, Dublin, hoped these officers could eventually be divided up and deployed to the provinces to support its 5th and 6th Division intelligence staffs, but it decided to keep it in Dublin under the command of the Dublin District Division, General Gerald Boyd, commanding. It was known officially as the Dublin District Special Branch (DDSB) and also as "D Branch". In May 1920, Lieutenant Colonel Walter Wilson arrived in Dublin to take command of D Branch.

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