During the Third Age, the Necromancer built Dol Guldur on the hill of Amon Lanc, and this part of the Forest was under his influence. During the War of the Ring, Dol Guldur was torn down by the Elves of Lórien (who dwelt immediately to the west across the Anduin); and after a meeting with the Elveking Thranduil and the renaming of the cleansed Forest on Yestare, Celeborn claimed the woods south of the Narrows.
Celeborn ruled the realm into the Fourth Age, though he did not remain there long. After a span of only "a few years," he retired to Rivendell to stay with his grandsons, the sons of Elrond. It is unknown if East Lórien continued as a realm after the departure of its founder, and if so, who may have succeeded him – if anyone. All that is known is that "in the Greenwood the Silvan Elves remained untroubled" for some time thereafter.