You all probably know that Kings cannot retool, that is, go through training to get better armor / sword upgrades. You cannot put them into the queue. The game will not let you.

Your princes, however, can retool.

So what happens when the prince next in line for king is in the queue to be retrained, and your king keels over from the Fandango Fan Dancing Disease making the rounds of your kingdom?

As you all know as well, when your king is crowned, he magically teleports to the most developed area of the kingdom and becomes a rearing horse instead of a guy in armor icon. They give him a big honkin wax seal and a foofy robe, a crown resplendent with tonnes of jewelry ransacked from other less fortunate kingdoms, and he gets to call everyone thee and talk about himself in the third person plural. ("We are pleas'd to see thee.") But if he's also in a queue, you've got a ticking time bomb that will end the world as you know it, or at least that iteration of the game. Cause the moment that king's unit hits the retooling factory, you'll see your screen go black and then you'll be looking at that stupid "Send error message to microsoft, as if they could or would do anything to fix it?" message.

So it went:
Me: (Noting there is an icon in the queue for the king's unit that has 0/0 stats. 0 men, 0 valour?) WTF? (Try to remove it; not successful. Hit "End Turn button.")

Game: Crash! Burn!

Me: !$#*^@&!#&*(#&*(~!

I blamed the French, since they're the largest faction in my game and they're everywhere, but when I went back to my saved game, I made sure the prince first in line for the king wasn't in any retooling queues, just to be sure. Success.