The Three Kings of the East

The Three Kings Alliance, or the Three Kings of the East, was founded by three heroes of the dark elves who had seemingly been around since the dawning of creation alongside other paragons of the Drow. They were Morvala, Karesh, and Xanvani; before their formation of their alliance, these three battle brothers guarded the Obscuran Mountains for millennia against the forces of everyone who would seek to do the lives of the dark elves harm as they scattered across the mainland and tried to form their own communities and families. For many thousands of years, these three garnered skills and capabilities for their time in the savagery of the past.
However, things could not remain as they were, the elves needed to start building a society greater than themselves, but this was not the land to do it in. There were too many threats, challenges, and other races who would like nothing more but for these blighted mountain walkers to just disappear. So instead, the three gathered as many possible followers as they could, and staged an exodus from the mainland, in an effort to forge a new path for their peoples. Each would be a King of his own making: Morvala the Mountain, Karesh the Dark King, and Xanvani the Seawalker. They decided to divide into threes, and as brothers they would reunite when they had conquered lands and made a home for their people.
Morvala went to the north, and there he found monsters, flying lizards, giant wolves with teeth that could rend the flesh off bone in a single bite, and inhabitants already populating these islands he would later claim as his own. He tamed the monsters, made peace with the tribes, and used his might and strength to become the barbarian king of the north, ruling through ancient law and practices of strength and wise council of elders, for those who lived longest knew best.
Karesh went into the central island that split the sea in two, though his journey was longest, he found a place filled with dwarves and humans, living in a tense war like relationship for as long as they could remember. So he spoke to either side and convinced them that he would help them destroy the other. Instead he put each under his rule and enforced a peace through dominance. For this they would hate him, but he gave them knowledge, employed they to build the great cities that would one day be the jewels of Avamor, and protected them under his watching eye despite his domination of their civilizations.
Lastly came Xanvani, who swept out to the south, and ignored the gigantic islands off the coast of the mainland, fearing that there were already too many that he could not overtake. He went even further south, and found the southern islands, a major one with three satellites, and then quite possibly hundreds more smattering about the southern reaches of the Sorrows . They were filled with more dangers than the others had faced combined, between sea monsters, savage tribesmen, and hungry beasts on the land, it was a death trap. Xanvani used his seafaring to one by one take each smaller point as his own, recruiting the savages and feeding the people with the bodies of the sea beasts and the monsters of the islands, and piece by peice he built a nation of those who sought more and more glory under the banner of the one who empowered them, eventually becoming Xanvani's powerful fleet that could rule the Eastern Sorrows.
When the brothers reunited in the center of the Sorrows, they boasted to one another their accomplishments, Morvala had overpowered the monsters and employed the strong to his rule, Karesh had outsmarted the natives and deceived them into accepting civilization, and Xanvani, the most empathetic of the three, had rallied those who came across the fly under his banner for glory and riches abound. Morvala and Karesh were astonished he could accomplish all of that with him having the weakest of followers form back home. They titled Xanvani as the true winner in their attempts to go forth and secure their own kingdoms.
They all celebrated, and finally made the oaths of protection and trade known as the Three Kings Alliance. With it, they ensured the East would swell with great trade for centuries before the Empire was even a figment of someone's imagination. Morvala supplied bounties a plenty of game and livestock, of grains and fruits, and was able to control his people and make them thrive as warriors and wise men, great workers and farmers. Karesh supplied educated laborers, mined and processed ores for weapons, ships, and buildings, lumber, and clothing. Xanvani, unable to use a vast majority of the natural resources, instead became a trader, being the ferrying force that shuffled and shipped the goods around to not only his brothers but to the humans of the east, to the south, and into the mainland. He outstretched his arms and showed the world at the time what the free men of the south would do and what they could offer, and they were traded back with, and became exceedingly rich. Xanvani, for his part, shared his wealth among the people and among his brothers.
Eventually, over the generations, the three Kings of the East were recognized far and wide by everyone who had dealings with them, great powerful kings far to the East who would come aboard with ships laden with weapons, cloth, gold and silver, lumber, iron, steel, meats and grains. It helped those on the mainland, those scattered about every which way, and those who were willing to lend their ear to another ever increasing amounts of wealth and prosperity. It helped to fuel what civilizations came before, no matter how small, from the south to the north. While Morvala was a barbarian, and Karesh was a mastermind, Xanvani was a freeman who wanted to see the world unite under a banner of true freedom to claim all that was theirs and to persist in the safety of others.
It couldn't last, when the Empire of Dusk arose, originally thought to be some kind of warring states period for the Dark Elves of Obscura, they came in hard and fast against Amora, the capital island of Morvala's Northern Kingdom. He was a skilled combatant, he broke the backs of many a commander the elves threw at him until they brought in a super powered monster known as Avernus the General. He toppled Morvala before the other two even knew what was going on, forced him to kneel, and decapitated his council. The other Kings would not take the humiliation of their brother lying down, and formed a massive navy, and stormed the imperial forces, but they had two women, known as Tearful and Gazer, who using pendants around their necks, destroyed half the navy before it ever reached the enemy. Those that survived had to contend with soldiers in glowing plates of armor, wielding bows on large pieces of wood that shot out arrows with such a rate of speed it tore into the numerous storming sailors like a swarm of bees. Their weapons using some kind of magic imbued within them, and shredding the numerical superiority away.
When all was said and done, the Three Kings were forced into a humiliating treaty, and saw their lands taken under the domain of the Empire of Dusk, Morvala saw it hardest, with Karesh simply having to forfeit his lands due to the massive presence of soldiers that soon flooded it and took command of his people, but Xanvani was far away, and scattered about islands, with many a soldier loyal to him. Where his brothers were broken and powerless, Xanvani was a thorn in the side of the Empire. He rebelled, bucked hard, and often, and though eh was still forced to concede to the power of the Empire, he did not do so lightly and never completely. He became known in this time as Xankresh Avani, the Pirate King alongside his former title as Xanvani the Seawalker. The Empire had tried to kill him, so many different times, but each and every time he'd slip away, or outclass whoever they threw against him. Despite his smaller stature in relation to the other Kings, and despite his kingdom having not focused on warfare or weapon's production, he was a mighty soldier-king who clashed with even the best and brightest officers of the Empire and won.
He'd lost his kingdom, but he would not let the Empire have it either, and for the duration of its reign, the Southern Kingdom of Nagari was a hellhole breakaway province where no legitimate ruler could be suffered to stay, forcing the Empire to allow for Xankresh to keep his power in the region, nominally, until such a time they could absolutely crush him under their boot heels. They couldn't just risk Avernus or their precious seers on such a task, the Empire was in a constant state of growth and stability was key, having them organizing things and being held in reserve was of greater consequence. Ironically, Xanvani still paid his taxes, and still forced the hand of the bureaucrats to supply his people, or he'd be setting off explosions throughout the Empire's most populace cities, and he meant it. The Pirate King was not above terrorism for the sake of his people...