A little about the theme: so I tried making something that felt Eastern Mediterranean but would still be different enough. So I made one main culture, where most heroes and villains are from, and a few characters come from foreign cultures. I made the skeleton of a story to help myself with the design. There are a few features that are common to the main culture: like the skirt, the braids, the blue color and dagger on the belt. Then there is a foreign empire, in the same fashion than the Persian empire. So that I can put characters that come from different cultures (they have been conquered by the empire).
I gave a little role to play in the story to each character, so that they would have some personality. The basic story is this. The King has been removed from power by his oldest son, he managed to escape with his life and intends of reclaiming the throne. The new king made a pact with the empire, they would help him take the throne and he would be their ally.
Also there are two heroes (prince and bodyguard) that have a little dynamic. they fight together, one holds a heavy shield and the other one attacks from behind with a bow. This is an aspect of the culture. For the sons of the king, body guards are raised to perform this task. so that to make sure they would not betray their prince.
-A little extra flavor-
So the old king and his people are warriors. They are cruel and vicious. They value physical strength and victory in war. They follow any god that would grant them victory, but always make sure to keep their own happy. Their preferred weapon is the bow and they train on upper body strength and compete to see who can string the stiffest bow. They also give braids to their warriors once they have reached the proper age, and if one commits dishonor he has his braids cut off to mark him. It is common for the king to have many sons from different women, though he may only have one queen. and she must not be of foreign origin.
So the New King is the oldest son of a group of around 20 princes. and the prince is around the middle. Even though New King took the throne by force that is not seen as dishonorable by the other nobles. On the other hand having dealings with a foreign empire is. Because of this many have decided to aid the Old King instead of remaining with the New One.
The people from the empire are more "cosmopolitan". They are used to meeting new people from far away places. In contrast to The people of the Old King, that are pretty Xenophobic.
Also my idea is that during the "story" the king would die, leaving the fighting to his son, the prince. Since he makes for a more traditional main character.