The Driftwood Throne on Dragonstone

We don't know who got to drift mark slash Dragonstone first. The Valyrians claim it was a gift from the Merling King, which doesn't help us clear up whether it was a thing from Valyria or from Blackwater Bay. It's also possible the Valyrians co-opted an existing story on Driftmark. We cannot absolutely can't eliminate that idea. Certainly, merlings come up in plenty of places. They're sightings of them that are semi believable. There's even multiple species of them, apparently. I don't know why they've been the business of thrones to make friends. But hey, you have given humans a good way to make friends