New to Beyond the Sword is the ability to make colonies of your empire. To do this you must have at least three cities on a landmass other than your home continent (where the capital is). Opening up the domestic screen will then open up this option. Note that you can only form one colony on each continent; any other liberation on a continent which has a colony of yours already will immediately be given over to the preexisting colony. If a colony is mistreated, it may break off and form a completely independent empire, in which case it is time to "send in the troops."