The rings were made along with the others in Eregion and were forged by Celebrimbor. Those were locked away in one of the safes of Eregion, but all were captured by Sauron. He gave nine of them to nine kings of Men, three of which were Númenóreans and one was an Easterling.
The owners of the nine eventually became the Nazgûl.
The Rings of Power gave their wearer powerful magical abilities and gave them the ability to influence peoples' will.
On Men those effects could be special: The rings gave a very long life, but the wearer would begin to feel worn out and eventually fade away into a wraith. The nine kings given the rings turned into Ringwraiths because Sauron was able to take control of the rings.
In The Council of Elrond, Gandalf says that the Nazgûl kept their Rings by saying "The Nine the Nazgûl keep". However in most other references, it is mentioned that Sauron had taken them. Furthermore, Frodo doesn't see any Rings on them on Weathertop, and it is believed that if they did wear the Rings, they would have been fully invisible (including their cloaks).
It's possible that the line in the Council of Elrond represents Tolkien's earlier intention that the Nazgûl should still be wearing their Rings; if that's so, he later changed his mind and simply missed revising that sentence.
 Portrayal in adaptations
2017: The Lord of the Rings Online:
- The Nine Rings are named as "Orôm, the Warmonger", "Sâkhla, the Cruel One", and "Adâsh, the Foe-maker", given to the Lieutenant of Dol Guldur and two other Easterling rulers, respectively; "Jûru, the Herald of Mourning", "Mêbat, the Mirth-eater", and "Khânto, the Pain-giver", given to Haradrim; and "Sapthân, the Foolstone", "Nitîr, Terror's Sting", and "Ûri, the Heart-stopper", given to Númenóreans, the third of whom became the Witch-king of Angmar.
- ↑ "the Nine he [Sauron] has gathered to himself; the Seven also, or else they are destroyed." J.R.R. Tolkien, The Lord of the Rings, The Fellowship of the Ring, "The Shadow of the Past"
- ↑ "You saw the Eye of him that holds the Seven and the Nine." J.R.R. Tolkien, The Lord of the Rings, The Fellowship of the Ring, "The Mirror of Galadriel"
- ↑ J.R.R. Tolkien, The Lord of the Rings, The Fellowship of the Ring, "The Council of Elrond"
- ↑ http://oakroadsystems.com/genl/ringfaq.htm#Q0-InvRiders
|Rings of Power|
|The One Ring|
|(Narya · Nenya · Vilya)|
|(Ring of Thrór)|