Up until 1922 any Irishmen in the military would fall under British records as Ireland was under British rule until that date. Also many Irishmen decided to fight with the Allies during the Second World War and so joined Irish regiments within the British Allied Army. When researching your ancestors’ military career it is very important to know what regiment they served under. (Calvary, Guards, Foot, Corps (artillery Air, Engineer etc.)) Records can be obtained in a number of places. Online you can go to The National archives website. There you can view service records (via http://ancestry.com and pay a fee). A list of what’s available is at http://www.nationalarchives.gov.uk/records/looking-for-person/default.htm.
You can also write to the Ministry of Defense for your relative’s service records. Although you must prove you are next of kin/ related. The Veterans’ UK site gives details on how to do this here: http://www.veterans-uk.info/service_records/service_records.html
After 1922 any military records for Irish servicemen are held in the state. To request the service record of a family member you must write to the Military Archives at Cathal Brugha Barracks. Some of the info which will help to speed up the search is as follows:
- First Name and Surname
- Date of Birth
- Army service no.
- Address at time of enlistment
- Units served in
- Corps Served in
- Did they do Overseas Service, if so where?
Full contact details to write to are at the bottom of the page at http://www.military.ie/info-centre/military-archives.