To help:
The empire that spans over the three continents is the Magnus Empire.
The empire in the bottom of Vesta is the Republic of Naarus.
The empire in the bottom of Atlas is Federation of Parvulus.

There are 3 continents. The left is Atlas, the right is Vesta, and the top is Hypnos.

This is set in another planet, different from Earth. The three continents are big. That tip at Atlas? That little gap is actually 200 km, so the place is pretty big. It forms the whole planet.
This sets in 600 AD. The language they all speak is a varying form of English and Latin. I can't make a new language so I'm using English and Latin for the sake of simplicity.

There are three empires.
The Magnus Empire, The Federation of Parvulus, and The Republic of Naarus.
The youngest is the Magnus Empire (the Magnusian Public Library says that the capital was founded in the 320 AI) and the oldest is the Federation (NOTE: This is debatable because although most sources say that the Federation started in 198 AI, some say that it started in 201 AI, 2 years after the Republic of Naarus was founded (199 AI))

The three empires co-exist (somewhat) peacefully. Trading is prevalent here and normally each empire treats each traders from different empires a source of good wealth. But in territorial claims, they have some conflicts there.

Cordus, 15th of Mors 601 AI.
All three empires are at war with each other. Taking cities, killings and spying.
In a fragmented world, the deaths are high.

You are a new soldier. Can you stop the conflict or go along with it?

ORIGINS
There's this little small island in the sea. Big enough to fit one big city and two smaller cities. In 578 AI, all three empires invaded the island. Once there, they fought a horrible war that lasted only 4 years. After that, an agreement was made declaring that the city is neutral and everyone is welcome. The forces defending it is an amalgam of Magnusian, Federation and Republican troops, but not loyal to them.

Even though it's just 4 years, there are still some palpable tension between the three empires.
Fast forward to 589 AI. 5 cities near the Magnusian border declared that the cities are aligned with the Federation and so they became Federation cities. Fast forward again to 600 AI when the five cities is violently absorbed into the Magnus Empire.

The Federation is enraged at this and declares war on the Magnus Empire. On the other side, the Republican also declares war on the Magnus Empire 5.5 months later upon finding out the killer of the Assassination on King Roberts IV was of Magnusian origin.

CALENDAR SYSTEM.

Tersus Calendar ("The Correct Calendar")

Anno Imperium
"The year of our gracious Empire."

Solar Calendar, 360 days.
A year is divided into 12 months with 30 equal days that is in turn divided by 5 weeks, each week having 6 days.

First Day = Mustus ("The New Day")
Second Day = Cordus ("The Second Day")
Third Day = Gremium ("The Middle Day")
Fourth Day = Finalis Opus ("The Final Day of Labor")
Fifth Day = Otium ("The Day of Relaxation")
Sixth Day = Imum ("The Final Day")

First month = Initio ("The Beginning Month")
Second month = Secundo ("The Second Month")
Third month = Mense ("The Odd Month")
Fourth month = Stellar ("The Stars of the Month")
Fifth month = Juxta ("The Near Middle Month")
Sixth month = Medium ("The Middle Month")
Seventh month = Tragoedia ("The Tragedy Month")
Eighth month = Etiam ("The Even Month")
Ninth month = Frigus ("The Cold Month")
Tenth month = Mors ("The Month of Death")
Eleventh month = Terminus ("The End of the Month")
Twelfth month = Novus ("The New Month")

Unlike the usual history, the empires have a very slow Industrial Revolution. Right now their technologies are limited to making clothes, cutting wood efficiently, and expanding their economy.

The Federation uses to get more fish so that they'll get more profits in their main trading goods, which is fish (Fish in the West is big and savory and thus a lot of people everywhere likes it). The Republic uses the Federation's technology to build houses and get more grain and rice easier, since Grain and Rice is the primary trading good of the Kingdom since it's situated on the East.
The Magnus Empire uses it to cut wood faster and use metal efficiently to get more territories.