By last century do you mean 1999? I know a chap who enlisted at age 14 as a drummer/piper and rose to become pipe major. He's not that old. Lads aged 17 could be on active service and when I was a nipper you could enlist at age 16. My next door neighbor did that as he didn't want to do O levels and they had a spot for him in the RA.. That changed one day in March, 1971 (and I remember it chillingly well) when the PIRA murdered three Scottish lads, two of them brothers aged 17/18. One was found propped up with the beer glass still in his hand. I've had people who were in position to know tell me that Martin McGunness, who was at the White House this week, had a hand in the murders.