I’ve come up with three civilizations based on the ideas you’ve given me. There’s a vote, which is open to all patrons, to decide which one will share the island of Tir Thelandira with the wild elves. Here are the choices:
The Kiyaran Khanate:
The Kiyarans are horse-riding, nomadic people with a culture inspired by Turkmen, Tatars and Mongols. They rule a small empire on several distant islands.
20 years ago, five ships of Kiyaran soldiers were caught in a storm and destroyed near the remote island of Tir Thelandira. The survivors came ashore and met the island’s elven residents, who took them to their queen. The queen allowed the Kiyarans to occupy the island’s eastern plains and to tame the wild horses that lived there, giving them bows to hunt with and tents to sleep in. The Kiyaran soldiers were grateful and never made trouble for the elves, for whom they had great respect.
Recently, the Khanate, who had long thought the soldiers to be dead, began to hear rumors that they were alive on Tir Thelandira. A ship was sent to the island, which found the survivors. Their leader, First Lancer Bayar, returned with them to tell his story to the Khan.
After hearing it, the Khan saw an opportunity to expand his empire. The soldiers would use their knowledge of the island and its inhabitants to assist a larger army in the conquest of the elven lands. Bayar asked the Khan to spare the elves, who had saved the lives of his men, but the Khan refused.
The Khan’s brother was sent to Tir Thelandira with ships full of soldiers. First Lancer Bayar returned as well, agreeing to help, but secretly hoping that he and his men might find a way to stop the invasion.
Dhasran Colony:
The White City of Dhasra is a small, tremendously wealthy city-state built on the islands of a river delta. The river, known as the Golden Serpent, was named for the large amounts of gold dust that once flowed through it.
That gold is one of the main sources of Dhasra’s wealth, but lately the mines have begun to peter out. In response, the Raja of Dhasra sent out a fleet of ships to find new sources of wealth abroad. Several of these ships came to the eastern shores of Tir Thelandira, where they noticed a few bits of gold flake in the river. After a bit of digging, a large vein of gold ore was discovered.
Before long, a small mining colony was constructed on the island. The elves living to the west watched the Dhasrans warily, but did not act until they began logging the elven woods. The colonists were warned, but the warning was ignored and the elves retaliated. Swiftly and mercilessly, the colonists were slain to a man.
After several months, the Dhasrans returned to rebuild their colony. This time, they brought two legions of mercenary soldiers to protect it. Neither side has moved on the other, but no one expects peace for long.
Exiles of the Triumphant Dawn:
In a distant kingdom, the priests of the Triumphant Dawn once had thousands of followers. Their god was a righteous and benevolent deity, who encouraged those traits in his worshippers.
When the priests began to demand an end to the corrupt and tyrannical rule of the nobility, they made a great many enemies. The priests believed that, as clergy, they had no need to fear serious retribution. They were wrong. After a number of riots, the nobles began hunting down and executing priests of the Triumphant Dawn.
Realizing that they had failed, the priests fled the kingdom, settling on the distant Tir Thelandira. The High Priest asked the island’s elven Queen for permission to stay, which she granted on two conditions. First, the exiled priests would not expand their colony. And second, they would not attempt to convert her people.
The High Priest agreed, but soon violated the first condition. After the priests left, the nobles had turned their wrath against their followers. When the priests learned of this, they sent ships to bring them to Tir Thelandira. The colony of 150 turned into a colony of 5000. When the new colonists began proselytizing to the elves, the queen regarded it as a complete betrayal.
Relations between the two groups are tense, with some elves launching raids against the colonists. So far, the Triumphant Dawn have exercised restraint, but there are people on both sides pushing for a holy war.