The practice of territorial division originated in the dark ages of the Desolate Wilds, when the Human Emperor of the ancient times was still in the world, unifying the Human Realm and conducting the first-ever division among the human race.
In that era, the division among the Human Race of the Desolate Wilds was that of various territories within the Human Realm, dividing the Human Realm into five vast lands, each then further divided into hundreds of Human Race Territories.