(Could be called GENERALS)
The point of the warlord is to make it so that even if you have lost your entire army, you still have a chance to come back.
Your warlord gains experience and notoriety every time you win a CAMPAIGN battle (Not a random battle). As your warlord gains levels, your party will collect experience from fighting faster.
If your entire army is defeated, your warlord loses notoriety. If his notoriety is below a certain point, every battle will warn you that if you lose it, it will mean game over (And there's no reloading the game!) You gain notoriety from winning battles.
Notoriety also drains while you are moving your army about on the overmap, so you can't spend TOO much time moving around and leveling up.
Training - This is a small number which is added to all experience gained by everyone in the party during combat. It adds up!
Abilities - Most warlords get some kind of ability they can use during combat
You start with 50 notoriety. Each loss (or retreating) of a battle, depending on how much you lost and how much you killed, subtracts from your notoriety.
If you have high notoriety, you are more likely to find good events from Forts, and perhaps some other benefit.
If your notoriety is zero or less, the next battle you enter will warn you that losing this battle will mean game over.
YYYYY - Diplomat Warlord. Units cost less and can be recruited for less. Also has a better chance of good encounters from Forts. Gets the ability BRIBE in combat that can steal a unit once per battle, for gold.
XXXXX - Warrior Warlord. Combat bonuses.
ZZZZZ - Wizard Warlord. Spellcasting abilities.
ABCDE - Mounted Warlord. Gets bonus for mounted units, they're cheaper and some other bonus.