The Karmom, living by the sea, their sphere the northern coast, proficient seafarers and fishermen.
The Urstan, by the south coast, immaculate craftsmen, most known for trinkets, jewelery and the likes, some of which are still considered national treasures, and the rest either on exhebition or sold to collectors for stupendous prices.
The Trantok of the southeastern forests, unparalleled at working the land, their Tran'lan, which can be described as planners of cultivation, being much demanded consultants among the tribes;
The En'qual, housed in the steppes of the northeast, spiritual leaders, keepers of most revered sites, and the tribe bringing forth the most respected shamans.
The Anin, having their chiefdom between the others, therefore having developed a culture of disciplined warriors; most remarkably, they deployed felines bred and trained for war, territorial and protective, fiercely loyal animals the size of a Great Dane dog, the Sha'anini, called Daggercat in modern times. Those beasts these days are the national animal of Aningem Atron.
They shared a common language called Trin'lak, commonly accepted to be the predecessor of modern Atroni. Trade between the tribes was lively, at least during times they were not having skirmishes over holy sites edging on their borders.
More often than not, those skirmishes remained just that; simple skirmishes with few casualties, as the sites of those battles were sacred; mutual respect was mandatory.
And still, around 22 KA (Kaine Atron, 724AD), the son of En'qual's chief got shot in the back by an Anini archer while retreating from the Holy Site Rap Kabo, mortally wounding them in the process. En'qual's High Shaman griefed and retreated from society for a fortnight; when he emerged, he called out a holy war against the Anin, which he claimed had angered the spirits by defiling the sanctity of Rap Kabo. The En'qual went to war, finding the Trantok as their allies, while the Anin defended their lands, aided by the Karmom. The Urstan refused to take part in that war; their oracle warned them urgently.
At first, luck was on the side of tribe En'qual.
During one of the first battles of said war, the chief of the Anini, Ikron, fell to a stray spear not meant for him. His son, Atron, succeeded him, and turned the tide of that war, later known as Kabo's Bloodshed; it lasted for six years and demanded many a life.
Atron, the Anin and the Karmom subdued the En'qual and Trantok, but held no grudge; Atron mandated that the losses the two tribes had to suffer be made up for, that their homes be rebuilt and cultural sites restored. Throughout his reign, he worked to tighten the bonds between all five tribes, and quickly turned years of misery into a budding golden age of economic and cultural exchange and achievement, which came to be known as Aningem Atron, Atrons Realm. He married the daughter of Urstan's Oracle and had three sons and a daughter with her.
Seventeen years after his ascent, on the day of the the summer equinox of year 0 AP (Atron Pada, 746 AD), he called his firstborn son and the leaders of the four other tribes to him, to the sacred hill of ancestors of the Anin. The oracle of the Urstan, En'qual's High Shaman, Karmom's Windmaster and Trantok's Chief.
He revealed he was suffering a terminal illness, one that drained his strength and willpower, and bestowed rule over the tribes to their respective leaders, urging them to never wage war against each other again, and sending them to gather a council of their tribe's most trusted, which they would preside. Thus the Council of Tribes was created, which coined many of still common titles in Atronian politics and culture.
Atron himself departed that night, wandering to the mountains surrpunding Aningem Atron, where he presumably died. The leaders honored his request, and ushered in a peace that was not broken for over a Millennium by now. Atronia, Aningem Atron's capital, was built around the site of the First Council.