The Almighty Demon Empire was divided into Eight Provinces, a Royal Zone, and Three Forbidden Countries.
The eight provinces were called Outer Continents, Common Provinces, or defensive lands or whatnot… by the demon who lived in the Royal Zone.
The reason being, the eight provinces were actually a turtle shell or a protective shield created by the highborn demons to protect and by themselves enough time to prepare in case of an invasion by the east, west, and south side of the continent.
They take anything worth taking from the eight provinces and created the royal zone, which was the northern side of the mighty demon continent, and its area was around the four-tenth of the eight provinces.
The eight provinces known the northern side of the continent as the royal zone, but the upper echelon of the demon race called it the Royal Demon Nation. It was the nation where only royal demons lived, no commoners or lowborn!