Smaug attacked Erebor and Dale when the Dwarf king Thror ruled he killed many and plundered Erebor, and since lay on all the Dwarwish gold.
When Thorin Oakenshield, the new dwarf king came to reclaim Erebor, he sent Bilbo Baggins, the Hobbit to reclaim the Arkenstone that Smaug guarded. This failed, and Smaug headed out to destroy Lake-Town. Fortunately, Bard, a local Bowman, killed the Dragon using a Black Arrow, piercing its weak spot.
- Smaug was almost burried alive in molten gold by Thorin.
- He had a keen sense of smell and could sense the Hobbit even when invisible.