Aegnor was the youngest son of Finarfin, and the brother of Finrod, Angrod and Galadriel. He crossed the Helcaraxë with Fingolfin's host, since Finarfin himself had turned back to Valinor and his children went on without him.1
In Beleriand he and his brother Angrod held the northern slopes of Dorthonion, looking out over the green plain of Ard-galen towards Angband. They were the vanguard of Finrod's realm and, during the long Siege of Angband, among the closest of the Noldor to the enemy's gates.2
A late text, the Athrabeth Finrod ah Andreth, tells that he loved a mortal woman, Andreth of the House of Bëor, and she him. He would not wed her: the Athrabeth says that the Eldar did not marry in time of war, that he distrusted the Siege, and that the gulf of mortality lay between them in any case.3
His foresight was true. In the Dagor Bragollach, the Battle of Sudden Flame, rivers of fire poured out of Angband across Ard-galen, and Dorthonion, the first land in their path, was overwhelmed. Angrod and Aegnor were both slain, fighting at the front of the Noldor.4
Sources
Citations name the chapter rather than the page, so they work in any edition. The colour of each note shows what kind of source it is.
- Edited posthumously The Silmarillion, Unfinished Tales and Tolkien's late writings on the Elder Days, assembled by Christopher Tolkien from his father's papers.
- Edited posthumously The Silmarillion, Quenta Silmarillion, ch. 9, “Of the Flight of the Noldor”
- Edited posthumously The Silmarillion, Quenta Silmarillion, ch. 14, “Of Beleriand and its Realms”
- Edited posthumously Morgoth's Ring (The History of Middle-earth, vol. 10), “Athrabeth Finrod ah Andreth”
- Edited posthumously The Silmarillion, Quenta Silmarillion, ch. 18, “Of the Ruin of Beleriand and the Fall of Fingolfin”