Númenórean Lords who belonged to the Faithful colonized those lands in the Second Age. The title Prince was applied to them long before they arrived to Dol Amroth and so it is possible that these lands were referred to as belonging to 'the Prince' from as far back as the Second Age.
The land was traversed by Amroth and Nimrodel when they abandoned their lands to go to Edhellond. Nimrodel and her maidens were lost among the wooded hills, but Prince Imrazôr of Belfalas harboured and married Mithrellas, one of them. Soon ater, the Elves abandoned the nearby city of Dol Amroth and Galador took it.
During the War of the Ring, the nearby city of Linhir was attacked by the Corsairs of Umbar and the Haradrim and Men of Lamedon under Angbor tried to keep them off, until the Grey Company with the wraiths of the Oathbreakers arrived and ended the conflict.
 Other versions of the Legendarium
Christopher Tolkien notes that the name appears only in the Map of Rohan, Gondor, and Mordor, the label being on the east of an unnamed hillrange. The name doesn't appear in the general Map of Middle-earth. For the newer map for the Unfinished Tales, C. Tolkien put the label on the same location, but among the wider context.
C. Tolkien notes that while, in the original map, the label was put between the hilrange and Gilrain to the east, the name betrayed a connection to the Princes and thus the name would refer to the wider area that included Dol Amroth, farther to the west.
 Portrayal in adaptations
2014: The Lord of the Rings Online:
- Dor-en-Ernil was an area in the region of Central Gondor, located south of the Ringló Vale and west of Lower Lebennin. During the War of the Ring, it was attacked by Corsairs of Umbar and Haradrim. The fishing village of "Gaerlond" and the inland village of "Tungobel" were both burned, the lighthouse of "Barad Rill" was toppled, and the beacon "Dol Brannor" was seized by the Enemy. The river Gilrain and the city of Linhir formed the eastern border. The hills to the west, between Dor-en-Ernil and the Havens of Belfalas were mostly inaccessible but were identified in dialogue as the "Emyn Ernil".
- ↑ J.R.R. Tolkien, The Lord of the Rings, The Return of the King, "Map of Rohan, Gondor, and Mordor"
- ↑ 2.0 2.1 2.2 J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "The History of Galadriel and Celeborn", "Amroth and Nimrodel", note 14
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "Cirion and Eorl and the Friendship of Gondor and Rohan", note 39, p. 316
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "The History of Galadriel and Celeborn", Amroth and Nimrodel
- ↑ J.R.R. Tolkien, The Lord of the Rings, The Return of the King, "The Last Debate"
- ↑ J.R.R. Tolkien, "The Rivers and Beacon-hills of Gondor" (edited by Carl F. Hostetter), in Vinyar Tengwar, Number 42, July 2001, p. 12
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "The West of Middle-earth at the End of the Third Age" [map]