Erebor, became the home of Durin’s Folk after they were driven from their ancestor’s home of Khazadum. It was here that they discovered in the heart of the mountain, the great diamond, known as the Arkenstone. Around it they built a fabulous store of treasure. The fame of this dwarven hoard, spread far and wide, until it came to the attention of the Great Worm, Smaug. Smaug flew south from the Grey Mountains and destroyed the strionghold, of the then king under the mountain, Thror, and drove his son, Thrain II and a remnant of his tribe into the wilderness.