Age of recruits in the Roman Army

[Tarbicus]

I've always heard 16, but unfortunately I don't have a first hand source aside from what other people have said and quoted.

Also I suspect big enough to look old enough as in the US Army up to and including the Second World War.

I don't.

Many recruits were in their twenties. That's a broad stroke, and in time of crisis younger would be okay. But the documented average seems to be 20+.

It don't tie in with modern recruitment practice, but tough titty.