Each family's objective is to conquer for the glory of the kingdom you pertain to. You also have to build cities so that more units and income can be raised.
The game is resolved in turns and after each turn (4 hours) the General would get gold income depending on which lands he is viewing in the current map. Each land can have various different types of income.
Once a General becomes powerful enough, such as obtaining lands directly under his control and winning battles, he can revolt and form a new kingdom..
Go forth and conquer in the name of the King...