Thorin IThorin I (2035 - 2289 T.A.) - The son of Thráin, King of Durin's Folk.  He left Erebor on a quest for a new home.

 

"But Thorin I his son removed and went into the far North to the Grey Mountains, where most of Durin's Folk were now gathering; for those mountains were rich and little explored." ~The Return of the King (Appendix A)