We were playing Cities and Knights at the weekend and halfway through the game realised that no one had earned the largest army card. The reason behind this was that no one knew what it was earned for. A couple of us scanned through the rule book in search of the answer, but to no avail.
Having since looked at the Wikipedia page (linked above) I see that it's the player with the most knight points, but do the knights have to be active, and is there a minimum requirement?