I have been trying to research this but I'm not finding the information I need. Does anybody know what is the highest soldier rank feasible for a 21 year old to hold in the British army? I found a newspaper article about a 23 year old woman who was a corporal, but the British army website said this rank is achieved after 6-8 years AND after certain training. It sounds like she did very well to achieve that by 23 and it wouldn't be feasible at 21? This character is supposed to have been an unusually good soldier so he should have achieved the highest rank possible, but it must be possible. It's not a huge plot point, at all, but it's important to me to get it right. Any help gratefully received!