Joseph O ' Sullivan Joseph O ' Sullivan ( 25 January 1897 – 10 August 1922 ) along with Reginald Dunne , was a member of the Irish Republican Army , who shot dead Field Marshal Sir Henry Hughes Wilson on his doorstep at 36 Eaton Place in London on 22 June 1922 . He was hanged for the killing on 10 August 1922 at Wandsworth Prison . The event provided the inspiration for the film " Odd Man Out " . O ' Sullivan ' s father John was originally from Bantry , County Cork , and had moved to London as a young man where he eventually became a successful tailor . O ' Sullivan ' s mother Mary Ann O ' Sullivan ( née Murphy ) was also born in Ireland in Inniscarra , County Cork . O ' Sullivan was the youngest of a thirteen children all born in London , although only eleven survived to adulthood . As a boy O ' Sullivan attended St Edmund ' s College , Ware . On 25 January 1915 ( his eighteenth birthday ) O ' Sullivan enlisted into the Royal Munster Fusiliers , and later transferred to the London Regiment . O ' Sullivan served as a British Army lance corporal with the London Regiment during the First World War and lost a leg at Ypres in 1917 . On being discharged from the army in 1918 , O ' Sullivan was employed by the Ministry of Munitions and , when the war ended , was transferred to the Ministry of Labour where he worked as a messenger . The Ministry of Labour was located in Montagu House , which was later demolished and replaced by the present day Ministry of Defence . Montagu House was located adjacent to Scotland Yard and it is probable that O ' Sullivan used his position in the civil service to obtain information for the London IRA . On the day of the assassination , O ' Sullivan left work at lunchtime and did not return . During the course of his pursuit and capture O ' Sullivan shot and wounded two policemen and a civilian . Joseph O ' Sullivan was an active Volunteer with the London IRA and was named by Rex Taylor as being responsible for the shooting of the " spy " Vincent Fovargue on Ashford Golf Links , Middlesex . Forvarge was found dead on the golf course on the 5th April 1921 with a label pinned to his body stating " Let spies and traitors beware , IRA " . Fovargue was 21 years old when he died and had been an officer in the Dublin IRA . He had been captured and tortured by the Crown Forces and allowed to " escape " after promising he would infiltrate the London IRA . O ' Sullivan ' s brother , Patrick O ' Sullivan , was the first Vice Commandant of the London IRA during its early days in 1919 but was seconded to the Cork No . 1 Brigade for the period of the Anglo - Irish War . Patrick O ' Sullivan had also served in the London Regiment during the First World War along with another brother Aloysius , who was discharged from the army in 1916 suffering from shell shock . Patrick O ' Sullivan was also wounded in a gas attack during the First World War . Patrick O ' Sullivan fought with the anti - Treaty IRA during the Civil War and was wounded in action ten days after his brother was executed . Shortly before that , Patrick had crossed over to England in order to participate in an attempt to rescue the two men . In the year after their execution , John O ' Sullivan tried to have the remains of the two men released in order that they could have a proper burial . However , it was only after the abolition of hanging that the law was changed and Patrick O ' Sullivan , with the assistance of the Irish National Graves Association , was able to arrange for the bodies of Joseph O ' Sullivan and Reginald Dunne to be repatriated to Ireland . In 1967 , after some political and diplomatic debate by the British and Irish governments , the British Government allowed the bodies of Dunne and O ' Sullivan to be exhumed . They were subsequently reburied in Deans Grange Cemetery in Ireland . O ' Sullivan ' s brother Patrick and another former comrade Harry O ' Brien accompanied the bodies from England to Dublin airport , where Patrick O ' Sullivan placed an Irish tricolour flag on Dunne ' s coffin . This was the same flag that Dunne had placed on the coffin of Terence MacSwiney at Euston Station when his body was returned to Cork in 1920 .