The Rings of Power or Great Rings are fictional artifacts from J. R. R. Tolkien's Middle-earthlegendarium. There were twenty Rings of Power. The Elves of Eregion made nineteen of the Rings of Power (and many other lesser rings) with knowledge obtained from Sauron. Sauron forged the twentieth Great Ring, called the One Ring or the Ruling Ring, secretly in the Fires of Mount Doom. Sauron created it to rule over all the other rings, and he put a great part of his power into the One. The Elves realized that Sauron wished to control them, and refused to use the rings. Sauron made war on the Elves and took possession of most of the Rings of Power, but the Elves fled Eregion with the Three Rings, the greatest of all the rings forged. Sauron gave the Seven Rings to the Dwarf-kings (although according to Dwarvish tradition the Elves gave one of them to the Dwarf Durin III) and the Nine Rings to Mortal Men. The Dwarves used their Rings to establish their treasure hoards, but they did not submit to Sauron. Dragons destroyed three of the Seven Rings, and after Sauron's return he recaptured the remaining four. The Men who had received the Nine Rings came under the power of the One Ring and became the Nazgūl, the Ringwraiths.
The Three Rings of the Elves of Eregion were forged by Celebrimbor alone, and were never touched by Sauron. They were called Narya, Nenya, and Vilya. They remained hidden and their whereabouts were not revealed until the end of the Third Age, after the One Ring is destroyed, and the Dark Lord Sauron was overthrown.
A verse that summarizes the Great Rings and their ownership is an important part of the lore of Middle-earth. It translates as follows:
Three Rings for the Elven-kings under the sky,
Seven for the Dwarf-lords in their halls of stone,
Nine for Mortal Men doomed to die,
One for the Dark Lord on his dark throne
In the Land of Mordor where the Shadows lie.
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
The Rings apparently granted the ability to see things which are normally unseen, such as Frodo Baggins' ability to see Galadriel's Ring when Samwise Gamgee could not or various instances of perceiving things in the wraith world while wearing the One.
Elrond hints at the possession of the three rings during the Council of Elrond in Rivendell, in The Fellowship of the Ring, advising that that neither he, nor Lórien, nor the Havens have the power to withstand the might of Mordor.
The One Ring was destroyed in the Sammath Naur at Orodruin, where it was originally forged, in The Return of the King, causing the downfall of Sauron and the undoing of all he created with it.