Ring of Durin

One of the Seven Rings of Power given to the Dwarf-lords. The Ring of Durin was unique in that it was granted by the Mírdain of Eregion to their ally Durin III; the other six Dwarf-rings were captured by Sauron after Eregion's fall, and used by him in pursuit of his goal of domination. Regardless of its source, though, Durin's Ring of Power was tainted by Sauron's corruption, as Durin's heirs discovered to their cost.

The line of Durin's Folk suffered a string of calamities through their history, being driven from Khazad-dûm, and later from Erebor, until the royal line of the greatest and most ancient line of the Dwarves was reduced to a lowly existence in the Blue Mountains. The last of the holders of the Ring of Durin was Thráin II, father of Thorin Oakenshield. Driven mad by longing for his lost home of Erebor in the distant east, he set out in search of it, but in the Wild he was captured by the agents of the Dark Lord. In the pits of Dol Guldur, the Ring of Durin was taken from him: the first of the Seven to be made was the last to be lost to Sauron.