Provinces

The subdivisions of a shard are known as provinces. Each shard has a varying number of provinces based on its size and shape.

Diplomacy

When you first decide to conquer a province and bring it under your control, assuming you have a high enough level of diplomacy, you'll be able to negotiate with the locals. By paying them cash or giving them something else they want, you can buy their loyalty and invite them into your realm without bloodshed.

War

Of course, if you're not in the mood, you can strike down their offensive and, frankly, smelly army and rebuild from scratch.

Distance

How far away a province is from your castle is a consideration. The further away it is (by counting provinces between castle and province), the harder it is to conquer and the harder it is to hold on to. As a rule of thumb, the longer it takes your hero to walk there, the more difficult that province is going to be.

Exploration

Every time you take over a province, as you can imagine you only see a small tiny fraction of the province while you are conquering it. By sending a hero to the province to explore it further, you can increase the exploration level of each province -- finding new and secret locations like underground temples, dark forests, and dungeons.

Explore every province (when you have time) until you reach 100% to get all that you can out of your province. Any province that is not fully-explored has a cap on it's population. Also, this is a great way to train your heroes and troops. Just keep in mind that deeper you explore your province, the harder the enemies will get.

Provincial Towns

You have no say over how the towns in the province grow or maintain themselves -- which is nice because don't you have enough on your plate already. You're a demigod, after all.

However, you can construct three buildings in a province to help it along. Buildings like taverns and breweries not only generate more revenue (increasing your gold in the process), but can provide critical resources to keep your citizens happy (or drunk, as the case may be) and not rioting.

Pyrrhic Provinces

While it's generally a good thing to pick up provinces along the way, some provinces are more trouble than they are worth. They have a constant stream of bad news and are always asking for more gold to bail them out of some jam they got themselves into. Beware these ne'er-do-wells.

Corruption

As you can imagine, provinces far away from your castle can become quite corrupt, requiring you to show up with a small force and crack some heads.

Guards

You can assign guards to maintain law and order in troublesome provinces. However, as provinces grow (in size and/or ire), you will have to assign additional guards to protect your interests. You can construct special buildings to improve and diversify the types of guards you send out.

Even More Corruption

Some guards are just filthy corrupt. They'll glean some of your tax revenue for themselves or -- debateably, even worse -- they'll eat a few of your citizens. You'll have to root them out and have them killed.