A world divided in parts, with people doomed to be eternal rivals.

Fantasy

Tewyn was originally created by three deities: Staera, Lux and Tenebris. They each chose a part of the world, and shaped it how they wanted. Lux shaped the Light Side, a white, bright land, while Tenebris formed the Dark Side, a much darker version of the Light Side. Staera did something different though. She made a natural place, with many animals and plants.

Tenebris, Lux and Staera came together, sometime after the creation of the world. It was for one reason: they were lonely, and all three desired company. They didn't get along well though, so they created a new species: humans. The humans were divided among Lux and Tenebris, giving them similar magic to their own, although Staera decided not to.

The humans lived, and thrived on their Side. However, Lux and Tenebris were quickly becoming rivals, both wanting to rule both west and east. They knew of Staera's domain, but left it to be, as Staera had made a pact with both of them. The humans started fighting, following the wishes of the Deities that had created them.

Eventually, the humans found out about the Wilderness. Some started worshipping Staera besides their own Deity, while others only wanted to conquer this new land. The Balance Believers, as they called themselves, didn't let this happen though.

The Balance Believers created powerful barriers to ward off those who intended harm to the Wilderness. They built small communities, and temples where they worshipped Staera.

However, millennia passed, and Staera was forgotten. The temples were abandoned, and the towns were lost in time. Now, Staera still exists, though almost no one remembers her, or her followers from ages ago. She is still watching over the War between Sides though, limiting the powers of both Tenebris and Lux. If she wouldn't, the War would be decided, killing everyone of one Side in a single strike, making it only one Side forever.

The same as on Earth, although there is magic added that has no scientific explanation yet.

There are 8 main types of magic, almost all have a limited group of users. No one can use more than 2 types, and some types can't have a secondary magic. The types are:
Light Side:
Light Magic
Fire Magic
Air Magic
Dark Side:
Darkness Magic
Water Magic
Earth Magic
Balance Magic:
Healing Magic - secondary type
Spell Magic

About the technology of the Roman Empire. The people are very intelligent, but many are focused on war, and are not interested in inventing things.