Has anyone else had this happen?

In my current campaign (English, early, expert [VI 2.01]) my King was in Flanders and the French launched an attack. When I started the battle, the pre-battle screen showed his newly-matured 16 year old son was the general, having 5* as opposed to the King's 4*. In the battle itself there was a 21 man unit of Royal Knights (the king) as an ordinary unit - no crown or anything!

This has never happened before, and as far as I know it shouldn't happen, cos the King is supposed to always take command when he's on the field. I can only guess that it had something to do with the new prince coming of age that year, in that province. The King had a full stack, and obviously the Prince was a new unit.

Most strange..... especially as after the battle the King got the extra command star and "skilled defender" virtue.