October 29th, 2023

Eregion was a realm of the Noldor in Eriador during the Second Age, called Hollin by Men. Both names were due to the abundance of holly trees. Holly was used as a token by the Elves who inhabited the land.1

The borders of Eregion were a low ridge crowned with holly trees in the north2, the Misty Mountains on the east (where lies Khazad Dum), the River Gwathlo (Greyflood) on the west3, and the River Glanduin (Swanfleet) on the south.4

Eregion was founded in SA750.5 Unfinished Tales gives this founding as the date work began on its chief city, Ost-in-Edhil. That version also says it was founded by Galadriel and Celeborn, while the versions in The Return of the King and The Silmarillion mention only Celebrimbor as lord of Eregion. (The lack of an indefinite article would tend to imply the definite, i.e. "Balin (the) Lord of Moria", "Gimli (the) Lord of the Glittering Caves, or "Faramir (the) Prince of Ithilien." One would expect then Celebrimbor being described as "lord of Eregion and the greatest of their craftsman"5 that he would be the ruler of that land.)

The friendship between the Elves of Eregion and the Dwarves of Khazad Dum was the closest friendship between Elves and Dwarves.5,6 There ran a highroad from Ost-in-Edhil to the gates of Moria, following the course of the Sirannon that flowed from the Misty Mountains. The road was bounded on the Moria-end by two great holly trees, denoting the border of Eregion.1 Both had great profit from eachother, making Eregion "far stronger and Khazad Dum far more beautiful than either would have done alone." 7

The Tale of Years in The Return of the Ring says Sauron (as Annatar6) came to Eregion in SA1200 and won over the Elven smiths. The version in Unfinished Tales says that he won them over so thoroughly, he encouraged them to wrest rulership over Eregion from Galadriel and Celeborn between SA1350 and SA1400. They succeeded and Galadriel left through Moria to Lorinand(later Lothlorien). Celeborn stayed, though from then on he had no real authority.

The Gwaith-i-Mirdain gained much knowledge from Sauron and reached the height of their skill around SA1500. This is when the Rings of Power were forged. Unfinished Tales says Sauron departed Eregion around this time. Around SA1590 the Three Rings were completed, and about ten years later the One Ring was forged by Sauron in Mordor. Celebrimbor realized what'd been done and took measures to secure the Three.

The War of the Elves and Sauron began officially in SA1693. Sauron invaded Eriador two years later after the Elves refused to surrender the Rings. Gil-Galad sent Elrond with a force to aid Celebrimbor, but it wasn't enough and he came too late. Eregion was laid waste within another two years. What was left of the inhabitants retreated northward with Elrond and founded the refuge of Imladris.

According to Unfinished Tales, Celeborn made a sortie against the scouts and vanguard of Sauron's invading army, and while he was able to drive them back and join with Elrond's force from Lindon, Sauron's numbers were great enough both to hold them off from returning to Eregion and to fully invest in his invasion. Sauron captured the House of the Mirdain and there gained the Nine Rings, among other works. Celebrimbor was taken alive and tortured for information. He gave up the Seven Rings, but refused to divulge anything about the Three and was eventually killed.

Sauron conquered all of Eriador by SA16995, using Celebrimbor's arrow-riddled body as a banner.7 Sauron was at last driven from Eriador with the aid of the Numenoreans in SA1701. Unfinished Tales says the first White Council was then held, and it was determined a stronghold in East Eriador should be maintained at Imladris, not Eregion.