EĂ€rendil is TĂșor's son & father of
Elros (First
King of NĂșmenor) and
Elrond, their mother being Elwing daughter of Dior, son of
Beren and
LĂșthien: so the problem of the
Half-elven becomes united in one line. The view is that the Half-elven have a power of (irrevocable) choice, which may be delayed but not permanently, which kin's fate they will share. Elros chose to be a King and 'longaevus' but mortal, so all his descendants are mortal, and of a specially noble
race, but with dwindling longevity: so
Aragorn (who, however, has a greater life-span than his contemporaries, double, though not the original
NĂșmenĂłrean treble, that of
Men). Elrond chose to be among the
Elves.
His children â with a renewed Elvish strain, since their mother was
CelebrĂan dtr. of
Galadriel â have to make their choices.
Arwen is not a 're-incarnation' of LĂșthien (that in the view of this mythical history would be impossible, since LĂșthien has died like a mortal and left the world of time) but a descendant very like her in looks, character, and fate. When she weds Aragorn (whose love-story elsewhere recounted is not here central and only occasionally referred to) she 'makes the choice of LĂșthien', so the grief at her parting from Elrond is specially poignant. Elrond passes Over Sea. The end of his sons, Elladan and Elrohir, is not told: they delay their choice, and remain for a while.