In early AD it would have been a....?

I'm not sure why, but Ian is quite taken with the idea that he will drive when he is 16. It seems to be in his mind a lot these days. Anyway, we were reading about Franz Liszt who grew up in the 1800's when I mentioned that his father died when Franz was only 16. Ian said quite matter of factly, "old enough to drive a carriage." I thought it was so funny that in Ian's mind no matter the century, at 16you can drive whatever is popular! Too funny :)