I did fairly OK as a seleucid campaign, I think the key is to immediately take your diplomat up North and gain an alliance with Pontus and Armenia. They always agree (in my experience, but then I'm only playing on med camp map) so thats your northern frontier secured. Dont leave it too long or else Armenia will attack Hatra. Then you need to take Cyprus ASAP off the Egyptians. It will earn you HEAPS of money with trade, then strike down to SIdon and Jerusalem. Forget about conquering the Nile Delta, the Egyptian citites are too close together and can easily reinforce each other. In Antioch you need to build cavalry stables first up to get Elephants. Elephants will save you here, get two to three units in the army and use them to stomp over the Egyptian spearmen (from the side or behind). They are also very good at taking a charge from chariots and cavalry, you'll be unlucky if you lose one. You also need to reduce Antioch's taxes to low, you want it to grow as fast as possible to get your elite units. Once your city reaches 12000 pop, you can train silver shield pikemen and cataphracts/war elephants, and thats when your domination starts to begin In the west, try to take Halicarnassus as sson as you can, the rebels there are fairly strong with some units of cretan archers/merc hoplites, but your generals cavalry units will help out there, plus your own mercenaries. The Greeks will likely start eyeing you off, so when they attack (with mostly hoplites) counter with cretan archers/rhodian slingers plus some mercs and take Pergamun. Beseiging is the best bet, plus you dont need to massacre the pop to reduce unrest because their culture is Greek too. On your estern front, the Parthians are fairly manageable if you keep a healthy garrison in Seleucia as they usually try and find easier prey in the rebel cities. Your main concenr is the two uits of cataphratcs they start out with, once they are gone you can strike quickly and take Susa off them. This deals them a nearly fatal blow for the whole game. Once you have your elite units, finish off the Egyptians and conquer whoever wins the Pontus/Armenia war (usually Pontus). THe challenge still isn't over though! By this time, the Romans will have dealt with most of their immediate opposition, and the Marian reforms are just around the corner! Try to take Greece and Sicily, then when the Romans are weakened you can take Rome. Your Silver Shield Legionnaires have same stats as post marian legionnaires, plus you get good pikemen and cataphracts/armoured elephants. Cretan archers and Rhodian slingers help here too. Its certaily a challengeing game as Seleucid! Dont build too many fleet, the AI opponent will always waste money on building several 1000 man fleets and domiate the ocean.