Irish military diaspora The Irish military diaspora refers to the many people of either Irish birth or extraction ( see Irish diaspora ) who have served in overseas military forces , regardless of rank , duration of service , or success . Many overseas military units were primarily made up of Irishmen ( or members of the Irish military diaspora ) and had the word ' Irish ' , an Irish place name or an Irish person in the unit ' s name . ' Irish ' named military units took part in numerous conflicts throughout world history . The first military unit of this kind was in the Spanish Netherlands during the Eighty Years ' War between Spain and the Dutch . A notable example is that of Owen Roe O ' Neill . Britain . A significant number of Irish people , of all backgrounds , have served in the forces of the British Crown over the centuries . By the end of the 18th century and the beginning of the 19th century , well over one - half of the military forces of the British Army consisted of Irishmen ) , because of : - Irishmen with notable or outstanding overseas careers included : - Others were not born in Ireland , but were born into Irish families , such as : - Victoria Cross recipients : - The Victoria Cross , the British Crown ' s highest award for military valour , has been awarded to 188 persons who were born in Ireland or had full Irish parentage . Of these thirty were awarded in the Crimean War , 52 in the Indian Mutiny , and 46 in numerous other British Empire campaigns between 1857 and 1914 . In the 20th century , 37 Irish VCs were awarded in the First World War , ten in the Second World War . One has been awarded in Afghanistan in the 21st century to a Belfast - born soldier of the Parachute Regiment . Following the establishment of the independent Irish Free State in 1922 , the five regiments that had their traditional recruiting grounds in the counties of the new state were disbanded . They were : Canada . The Irish Regiment of Canada was the only Irish unit to fight in the Second World War . It also perpetuates the active service of the 1st Canadian Machine Gun Battalion from the First World War and the indirect service of the 190th ( Sportsmen ) Battalion , Canadian Expeditionary Force , and the 208th ( Canadian Irish ) Battalion , CEF . Served as 1915 110th Irish Regiment ; 1920 – The Irish Regiment ; 1932 – The Irish Regiment of Canada ; 1936 – The Irish Regiment of Canada ( MG ) ; 1940 – The Irish Regiment of Canada . The Irish Fusiliers of Canada ( Vancouver Regiment ) perpetuated the First World War active service of the 29th ( Vancouver ) Battalion , CEF plus the indirect service of the 121st ( Western Irish ) Battalion , CEF and the 158th ( Duke of Connaught ' s Own ) Battalion , CEF . Served as 1913 – 11th Regiment , Irish Fusiliers of Canada ; 1920 – The Irish Fusiliers of Canada ; 1936 – The Irish Fusiliers of Canada ( Vancouver Regiment ) ; 1946 – 65th Light Anti - Aircraft Regiment ( Irish Fusiliers ) ; 1958 – The Irish Fusiliers of Canada ( Vancouver Regiment ) ; 1965 – placed on the Supplementary Order of Battle ; 2002 – amalgamated with The British Columbia Regiment . The Irish Canadian Rangers perpetuated the indirect service of the 199th Battalion Duchess of Connaught ' s Own Irish Rangers , CEF . Served as 1914 – 55th Irish Canadian Rangers ; 1920 – The Irish Canadian Rangers ; 1936 – disbanded . The 218th ( Edmonton Irish Guards ) Battalion , CEF lacks perpetuation . The colonel had Irish ancestry , but the largest group of its men were recent eastern European immigrants from the fringes of the Austro - Hungarian Empire who spoke Ukrainian but would have had Hungarian citizenship . This combined with the 211th ( Alberta Americans ) Battalion , CEF , to form the 8th Battalion , Canadian Railway Troops , which served in France building and maintaining railroads . France . Notable Irishmen who served in the French military include Germany . In the First World War , Imperial Germany tried with the help of Roger Casement to recruit an " Irish Brigade " from Irish - born prisoners of war who had served in the British Army . By 1916 only 52 men had volunteered , and the plan was abandoned . In the Second World War an even smaller number volunteered to join the Wehrmacht of Nazi Germany and were trained at Friesack Camp . Separately some IRA sympathisers planned certain operations with the Abwehr that were generally unsuccessful . Papal States . An Irish Brigade led by Myles O ' Reilly attempted to save the Papal States in 1859 – 60 during the Second Italian War of Independence . Portugal . Kingdom of Portugal Spain . Spanish Civil War ' Irish ' named units in Spain . Historical Spanish Cvil War ( 1936 – 1939 ) United States of America . ' Irish ' named units in the United States . Many of these units have their origins from the participation of Irish - Americans in the American Civil War . American Revolution Loyalists American Civil War Union Army Confederate Army Modern era Admiral William M . Callaghan Chairman of the Joint Chiefs of Staff Michael Mullen