Thorin II Oakenshield, son of Thráin II, was leader of Durin's folk and "King under the Mountain". He is the leader of the group that tries to take back the Lonely Mountain from the dragon Smaug in "The Hobbit". He is wounded in the "Battle of Five Armies" and dies. Dáin II Ironfoot becomes "King under the Mountain" after him. Thorin has a sister, Dís, who has two sons Fíli and Kíli.