Below found King Phillip's detailed strategies in Stronghold Crusader.
Economy
Phillip's economy is rather small and is heavily dependant on iron. He constructs several iron mines to provide a stable income and to create armour and swords for his knights. He supplies his granary with apples and frequently buys in bread and cheese to boost his popularity through food variety. He places some woodcutters, but does not build any quarries (perhaps due to him using little stone for walls), leaving him vulnerable in the early game. He places good things up to the maximum fear factor and religious buildings to boost his popularity and troop morale.
He relies on very expensive buildings such as the cathedral and stables, meaning that at the start of the game, if he has low starting gold, he can be slow to build up a large army compared to other AI lords that use the relatively cheap spearmen and archers, such as the Rat or the Snake. This also means that it will be costly for Phillip to rebuild his castle if it is destroyed by fire or siege engines, although Phillip uses little gold anyway for troops, so it may not be too hard for him to recover.
Phillip produces few weapons, except in his largest castles, and in his smallest castles, he does not produce metal armour or swords, meaning he has to, rather uneconomically, buy in all the weapons needed for the production of knights.
Offense
Phillip is a lord who is heavily reliant on his knight raids for his offensive strategy. He sends knights much more frequently than either the Marshal or Emperor Frederick, and there can be as many as 9 knights in a raid. The knights' targets are outlying woodcutters' huts, farms, iron mines and quarries, but they will also attack other outlying buildings and will even turn to attack any walls and towers near these targets.
As well as these knight raids, King Phillip will, less frequently, send as his 'main' attacks, groups consisting only of spearmen, to besiege a castle. These groups are rarely very large, and even if they are, only a few attack if there is no breach in the castle, and the rest then return to his castle once the initial few advancing spearmen are inevitably killed. The lack of supporting missile units or siege equipment, makes these attacks rather wasteful and pointless (although of course because of his +5 positive fear factor, Phillip's spearmen are a bit tougher than the Rat or Snake's, having a +25 combat bonus), unless they are on a castle which is already being attacked by one of his knight raids. However the weakness of these 'main' attacks with just spearmen, before which Phillip taunts his enemies, means the most dangerous aspect of Phillip's offense, the knight raids, occurs without warning.
If he has a good amount of gold, Phillip likes to roll forward catapults, one by one, in the direction of the castle he has chosen to target.
Defense
King Phillip constructs castles unique in design. The castle front is of reasonable strength, containing thick walls with crenulation, two square towers with ballistae (but usually no archers) and a large gatehouse. It acts as a shield, giving the rest of the castle some protection against missile fire from the front, particularly as most of Phillip's castles (apart from the largest ones) have the keep with all his archers directly behind the protection of his large gatehouse, and he chooses not to put his archers on the towers, where they would be more easily shot at. The rear of his castle is much less well protected, being only covered with a single layer of moat and a small, ungarrisoned gatehouse. However knights guard all corners at the outside of the castle, with a particular emphasis on the less well defended back area.
Phillip sends either a few knights, some archers in loose formation or a group of spearmen to counter harassments. Small groups of archers, with a few knights amongst them, are deployed by Phillip to guard his farms and iron mines.