Dragons were once quite prolific on Sollette. They were the terror of the skies and caused all the races no end of trouble. But not long after the Great Divide, a human king declared himself the dragonslayer and waged a campaign to slay as many as he could. By the end of his life, he had slain fifteen dragons. Unfortunately the slaughter didn't stop there. It had become quite fashionable to slay dragons and nobles the world round were hunting them down. Eventually the number of dragons visibly dwindled, until no one could find a living dragon.
As it turned out, they were not extinct, but had come together and decided to move where they wouldn't be bothered anymore. They found a massive island and all the dragons settled there. Although there were indigenous people on this island, there had been no contact with the mainland and they did not know about the dragonslaying. Just to be safe, the dragons used their magic to alter their shapes and blend in. Some became one of the humanoids that lived on the island, but others spread out and became animals. Within a thousand years, there wasn't a single creature that didn't have any dragonblood in it on the island and the pure dragons were no more. This is also when the first ships from the mainland found the island.
The dragons had passed on their fear of the mainland. Their ships were burned down and any survivors were slaughtered. Soon after first contact, they built a massive wall around the entire island, no one could enter without them knowing about it. They live in complete seclusion and are completely self sufficient on their own.
Even after hundreds of years they are still in seclusion. But lately there are rumors that they have been working on ways to become true dragons once more. No one knows if they have succeeded but since there aren't any dragons flying around, it is safe to assume they are still experimenting.