Grepolis is a browser-based, real-time strategy game set in antiquity. The objective of the game -- like most in its genre -- is empire building through conquest. However, capturing an enemy city requires a huge amount of troops. This, in turn, means a huge population is necessary to conscript legions of troops. It takes time to build a large population, but with a little bit of patience and know-how you can turn your village into a thriving empire.
Raise the level of your Farm as often as possible. Each additional Farm level will increase your population. Continue to do this until the Farm tops off at level 40. Save up resources so that Farm upgrades can be completed early.
Research plough technology when your Academy reaches level 22. The plough will allow your city's Farm to provide another 200 residents.
Build a Thermal Bath when you have a level 35 Farm, a level 24 Senate, a level 5 Harbor and a level 5 Academy. Do not build a Theater, Library or Lighthouse as you can only build one of the four buildings in each village.
Conquer additional villages. Each village you control will have its own Farm, technologies and special buildings. The more villages you control, the larger your population can become.