In the Dawn Era, around 6000 DE, dozens of eggs were left in the Coremeen marsh. Each egg contained a Graagvrii. They were left here as part of a survivalist experiment, to see if they could survive on their own. The one behind this was Semuanya, progenitor of the Graagvrii race. Semuanya advocated survival of the fittest ideals, but more importantly sought to spread his people far and wide, giving them the best chance of weathering the great war of the Dawn Era.
In the Demon Spawn War (8972 GE - 9493 GE), a Vedrii unit led by a demon commander under Baphomet, invaded Turgon. They warred with the Graagvrii. The arrival of the wood elves came about from this conflict. This Covenant unit helped the Graagvrii turn the tide against the Vedrii and their demon allies. After the war, the wood elves settled down in Turgon's south, the Vedrii settled down alongside the Graagvrii which they looked down upon as rabble.
In the Lith-Crillion Era, gray elves from the world Kriav were sent to live here. They were Gwildath colonists. They and their off-shoots, settled along the coasts, building grand port cities like Celanil, Nénharma, Cirongwathir, and formidable coastal bastions like Gilthoniel.
In Year 10 of the First Epoch, the Phael-Tetramord War (10 - 25) began. Turgon's elven states united against the scaly hordes of the Tetramord. The war took a turn for the worse when a group of elves decided to bring in outside aid. This summoning created the Ungorth Reddik Road, a rift linking the world Bal-Kriav with the demon world Abyssm. A demon invasion came from this gateway, driving the elves away, an evacuation that came to be known as the Turgon Exodus (13 - 25).
Today, Turgon is home to creatures alien to the world around them, most natives or descendants of people that came over from Abyssm. These are things with a demon heritage or those infused with abyssal energies. In the wetlands of Coremeen is the Ungorth Reddik Road, the source of these abyssal things. Following the departure of the elves and subjugation of the Tetramord, Turgon became real estate of one of Abyss's most powerful demon lords, the terrible Demogorgon.
Turgon's terrain is warped from abyssal energies. The island is often wracked with Evil Weather, winds unnaturally cold, acid rain, and other fell happenings. Fortunately for lands and seas near, this is contained by the Turgon Boundary Ward. This magical force field varies in shape. Due to this ill-defined shape, sea travel in the area can be particularly dangerous. On several occasions, ships have passed into the Abyss-tainted waters near Turgon and suffered attacks and destruction by the island's demons.