One Ring

The One Ring was an ancient artifact created by the Dark Lord Sauron in the Second Age for the purpose of ruling over the Free peoples of Middle-earth, mainly the Elves.
It was also known as the Ruling Ring, Great Ring of Power and Isildur's Bane (due to it causing the death of Isildur). In the Ring Verse it is referred to as Ash Nazg in Black Speech.
== History ==
In the year of the Second age, the One Ring was forged by Sauron to control the other rings in order for him to take over all of Middle-earth. However, the Ring is cut off by Isildur who defeated Sauron in the Last Alliance of Men and Elves and keeps it for himself. In a flashback of Fellowship of the Ring, Elrond reveals to Gandalf that he led Isildur to Mount Doom to destroy it. However, he was unable to do so due to its evil influence and left the mountain before throwing it into the volcano. Due to this, Isildur kept the ring until he was killed and lost it in the Anduin river.
2,500 years later, Gollum (then known as Smeagol) kills his cousin Deagol, taking the ring for himself and the River-bank hobbits cast him out of society. For five hundred years, the Ring remained in Gollum's possession.
== The Hobbit film series ==
=== An Unexpected Journey ===
The ring doesn't appear until the last thirty minutes of the first film. Bilbo Baggins, a Hobbit of the Shire and the series' protagonist, is separated from his companions, who were captured by Goblins, in the Misty Mountains, and lands in Gollum's cave with a nearly dead Goblin who attacks him. While Golluma nd the Goblin struggle, Bilbo takes the Ring from the ground and keeps it in his pocket.