Quote Originally Posted by econ21
One thing I could not get my head around in MTW was the difference between knights, men-at-arms and sergeants. In reality, was there such a distinction?

I'm guessing knights were distinguished primarily by social status, rather than military equipment per se. They would tend to have top of the line stuff, I suppose, but I'd reckon the warrior retainers of a top noble might be comparably equipped (and even skiled?) to a low status knight.

Men-at-arms in the historical references I've read tends to be a catch-all to include well equipped (ie armoured for melee) soldiers, including knights.

Sergeants - well, I just don't know what they are. In MTW, they seem to be fighters lacking the state-of-art armour and mounts.

I'm not sure how much it all matters for MTW2, although I have a hunch that in reality the knights and other men-at-arms would fight inter-mingled, rather than in separate units. And that men-at-arms should pretty much all have mounts (and be dismountable), as should knights proper. I guess all this is just a sacrifice we make for getting a more varied unit roster (and dealing with the problem of programming the AI to cope with dismountable units).
"Men-at-arms" were all well-equipped warriors, capable of fighting both mounted and dismounted, usually but not always of noble birth. The bread-and-butter heavy troops.

"Knights" were men-at-arms with the formal knightly status (although in the Early Middle Ages, simply the feudal heavy cavalry from any background serving under the assorted noble magnates). All knight were men-at-arms (and, after Early Middle Ages, aristocracy), but the opposite very specifically did not hold true - the ceremonies and rituals involved in aquiring the rank eventually became so expensive and elaborate that even senior nobility quite often simply could not afford them.

Sergeants were assorted lighter, non-noble "feudal professional" troops - lower landholding warrior class, salaried full-timers in cities, better milita troops, whatever. I understand the term covers quite a wide variety of reasonably capable "support" close-combat troops who provided the bulk of more competent infantry and lighter cavalry formations.