Plains
There are seven different types of Wildland: Plains, Hills, Forests, Grasslands, Mountains, Lakes, and Marshes. Cities can only be built on Plains.

Your current Nobility Rank must be at least Knight to be able to govern more than one city.

Once your Nobility Rank has reached Knight, you can identify a Plain on which to build a new city.

Occupy the Plain and make sure that your troops are carrying 10,000 Silver, Wood, Food, Iron, and Stone. These resources are required to begin construction of the new city.