Remember that during the time that Ireland was under the British government, Irish military personnel were in the British system, and their records would be at Kew, with all the other British Military records. The key to British Army archives is to know what regiment he served in, since there were some 20 cavalry regiments (horse), 3 guards regiments and near a 100 regiments of foot at one time plus major corps such as the Royal Artillery and the Wagon Train – not counting the many fencible (home defence) and yeomanry regiments!] for more click here