A long time ago there was only one place in the world were they could mine mithril which in itself was strange for normally it only fell from the sky. But here was a volcanic island, in a little chain of islands, way to the west of the mainlands that had a fantastic amount of mithril to be found anywhere anyone dug. The dwarves moved in. The dwarves took over.  After all it was the dwarves who found it. And they dug for mithril. And they mined for mithril. And they smelted pure mithril from the volcanic ore. They became rich, and richer. And they became greedy, and greedier. And this is  what happened.