King under the Mountain, also known as the King of Erebor, was a title held by not only the King of Durin's Folk, but also the person who lived in Erebor.
People who held the title []
Thrain I †- Father of Thorin the first who founded the Lonely Mountain as the kingdom. His descendant Thrain son of Thror is named after him. He also found the Arkenstone.
Thorin I † - Son of Thrain I and abandoned the Lonely Mountain to find the Grey Mountains
Thror
Thrór † - After the title was abandoned, Thrór returned to the Lonely Mountain and found the Arkenstone again.
