The Second Age
King of Khazad-Dûm, Lord of the Longbeards
He was given the name of the first Father of the Dwarves because he greatly resembles him in both appearance and manner. Indeed it is believed among the Dwarves that he was the reincarnation of Durin I, though whether this is possible is unclear.
During his reign in the Second Age, the Dwarves of Khazad-dûm struck a rare friendship with the Elves of Ost-in-Edhil in Eregion.