Below found the Caliph's different strategies in Stronghold Crusader.
Economy
In the first Stronghold Crusader, the Caliph runs a simple but effective economy. He gathers most raw materials, placing numerous woodcutters, 2 quarries, a mine and many pitch rigs. He builds apple farms for the granary and produces hops for ale. He sacrifices morale to boost production to maximum efficiency by negative fear factor. The Caliph utilizes taxes to an extent and is not stingy to give extra rations.
In Stronghold Crusader 2, the Caliph has a slighly different economy, producing the much more efficient bread for food instead of apples while still using ale to increase his tax rates.
Offense
In the first Stronghold Crusader, when attacking, he uses horse archers, Arabian archers and Arabian swordsmen supported by up to three fire ballistae. Slaves will be brought if his enemy has a moat. He is quite aggressive, which makes him a threat at the start of a game. However, as the player's defense mounts, his attacks become less and less effective. Of course if he starts the game with a lot of gold, or is left undisturbed in a position with good access to farmland, stone, iron and pitch, he can build up a very large army that may pose a threat to even a well defended castle.
In the first game, the Caliph is notable for harassing the enemy from the very beginning by sending hordes of slaves. Even when he is doing badly economically, he can usually still keep sending slave raids, and this makes him a constant threat. When he does have the finances, the Caliph sends catapults and fire ballistae after one another to demolish any hostile buildings in sight or to fire at tower walls and their garrisons.
In Stronghold Crusader 2, the Caliph still uses slaves for raiding, but backs them up with the new slave driver unit to boost their strength. As well as this, unlike in the first game the slaves are frequently backed up by small to moderate groups of horse archers in an effort to distract the attention of enemy archers (who will always shoot at ranged units first). For his main sieges, the Caliph uses the same units as in the first game, these being horse archers (which unlike in the original game, he wisely keeps on the move constantly), arabian archers, arabian swordsmen and slaves (backed up by a slave driver) together with catapults and fire ballistae.
Defense
In both games, the Caliph has one of the most distinctive castles, a long and rectangular structure with a lot of lookout towers on the walls. These lookout towers as well as providing a good vantage point for his archers, act as a screen making it harder for enemy missile troops to target the keep or interior of his castle. He likes defending with fire; pitch ditches surround his outer walls and Arabian bowmen are stationed in his towers who will ignite it with the slightest provocation. Fire Ballistae are placed near his outer walls. Like most of the other Arabian lords, the only European units he uses are engineers, whom he mans with boiling oil to support his Arabian fire throwers on the towers. In Stronghold Crusader 2, the Caliph also uses haybale launchers to create fire when troops approach.
His castle holds most of his buildings, so that there are no exposed buildings, except for his farms, woodcutter's huts and mines. This is mainly because the outer walls have pitch ditch to burn enemies. However this also makes his castle hard to set on fire with slaves, and with the screen of lookout towers and opposing fire ballistae and archers, it is also difficult to use fire ballistae to burn his interior castle buildings down. In addition to this, the interior buildings are well spread out so fire will not spread easily. Sometimes, usually only when he has the space, as well as his main wall, the Caliph also builds an outer low wall. This is to provide additional defence while the lowness of the wall allows his defensive fire ballistae behind the low wall to still be effective, and to be harder for enemies to destroy with melee troops.