The half-elven were given a choice to be counted as one of the Eldar (Elves), thus being immortal, or one of the Edain (Men), thus being mortal. In the list below, those who were counted as Eldar are italicized; those who were counted as Edain are not. Their actual mathematical descent from elves is in a fraction in parentheses.
The important half-elven were:
- Dior, son of Man Beren and Elf1 Lúthien. (1/4)
- Eärendil, son of the Man Tuor and Elf Idril. (1/2)
- Elwing, daughter of Dior and Elf Nimloth. (5/8)
- Eluréd and Elurín2, sons of Dior. (5/8)
- Elrond, son of Eärendil and Elwing. (9/16)
- Elros, also son of Eärendil and Elwing. (9/16)
- Arwen, daughter of Elrond and Elf Celebrían. (25/32)
- Elladan and Elrohir, sons of Elrond3. (25/32)
Eärendil would rather have chosen the kindred of Men, but he chose the Elves for his wife Elwing's sake, who chose the Elves. Eärendil's fate was special however: he was not allowed to stay in Valinor, but had to sail the heavens in his ship Vingilótë, the Silmaril of Beren and Lúthien on the prow, as a sign of hope for Middle-earth. Elwing built a tower in the Shadowy Seas and often met him on his return.
The heirs of Elrond, including Arwen Undómiel, also had the free choice of kindred, therefore Arwen could choose to be counted amongst the Edain even though her father had chosen to be counted as Elven. The heirs of Elros were not given this choice, but their lifespan was enhanced many times that of normal Men. In later times the Númenórean Kings, descendants of Elros, regretted their forefather's choice, and this helped lead to the Downfall of Númenor.
Dior was the son of Beren and Lúthien, and he was therefore also counted as Half-elven, as were his children with the Elf Nimloth of Doriath, Eluréd, Elurín, and Elwing. Eluréd and Elurín were killed, but Elwing was given her choice of kindred.
Arwen, daughter of Elrond married Aragorn heir of Elros, and thus the two Half-elven lines were merged in the Fourth Age. Their son Eldarion and their daughters were not counted as Half-elven, but rather as Dúnedain restored.
It was a tradition in Dol Amroth that Imrazôr the Númenórean had married an Elf, and therefore the Princes of Dol Amroth were of Elven descent, but they were not counted as Half-elven.
- Lúthien was considered to be of the Eldar, not the half-elven; however, she was technically half-elven since only her father was an Elf. Her mother, Melian, was one of the Maiar, an angelic holy being. Though she did actually give up her mortality so her husband would be brought back to life, she was still considered one of the Eldar and never of the half-elven or Edain.
- Eluréd and Elurín were captured by the servants of Celegorm and abandoned in the forest, thus dying before their decision as to their kindred could be made.
- We are not sure of whether Elladan and Elrohir chose to be of the Edain or the Eldar; this information is not given in the books. However, since their choice was expressed by whether they would follow their father to Valinor at the time of his own departure, and they were described as remaining in Rivendell, they are often said to have chosen the Edain.