did you have your taxes maxed out?
did you build roads?
did you build trade buildings of any kind?
did you build ports?
did you establish trade routes with other factions?
did you sell your map information for cash?
did you build farms?

the start of the game is all about building up your economy. once this is done, you can usually start expanding fairly rapidly. you dont' have to do all of these things at once, but piece by piece it all adds up.