Your army is composed of 4 different types of units: the basic soldier, the knight, the pikeman, and your elite unit.

Soldier

The soldier is the basic foot soldier. None of the other unit types may be directly recruited. They must be upgraded from a soldier. Furthermore, soldiers are the only military unit that may be sent in an aid package to other kingdoms. It can be argued, then, that the soldier is the most important unit to have in reserve. Also, soldiers are the only units that can be directly released to make your army smaller.
1 attack, 1 defense
cost: 100 gold
upkeep per hour: 1 gold

Knight

The knight is the primary attacking unit in any army. Although they tend to be weak on defense, they can punch through a defensive line fairly quickly with their mounts.
3 attack, 1 defense
cost: 300 gold, 1 soldier
upkeep per hour: 2 gold

Pikeman

The pikeman is an excellent defensive unit, matching the knight's offensive prowess. With a good number of pikemen, a kingdom is much less vulnerable to attack.
1 attack, 3 defense
cost: 300 gold, 1 soldier
upkeep per hour: 2 gold

Elite Units

Each hero type has its own elite unit. These are the most expensive and in return the most powerful units on the battlefield.
attack and defense vary by hero type
cost varies by hero type
upkeep per hour: 3 gold (0.2 for Automators)

Elite Unit Statistics

Hero Type	Name	Cost	Attack	Defense
Visionary	Defender	500	2	8
General	Elite	700	5	5
Warmonger	Berserker	500	8	2
Mogul	Legionnaire	400	3	5
Magician	Wizard	400	5	3
God	Infernal	???	???	???
God	Archangel	10000	1000?	1000?

Slayer	Assassins	400	6	2
Necromancer	Zombies	400	3	3
Automator	Machina	1000	5	5