[@shylarah] Academy for knights? Not so much - you request to be a squire at a young age and when the knight you're a squire of deems you ready, you take exams to become a knight (mix of martial and tactics probably). There [b]are[/b] royal knights, those who stand guard at the castle instead of protecting the lands. I need to add towns, now that I think of it...

Anyways, that role (royal knight) is applied for after becoming a knight. To become a knight commander, it would be more ... like being elected by the current knight commanders and the king/queen (or steward of the throne), but the king/queen vote only counts as one - so some knight commanders do get in, even if they voted for no. A tradition that's been instated for generations.

General ages are what you might expect - 12-20 are generally the ages of squires, 18-26 are knights, and probably... 24+ for knight commanders. I know it's not the [i]most[/i] realistic thing to essentially have generals be so young, but it's fantasy roleplay. =3

Hope that helps!