|Dead or Alive||Alive|
Tolkien gives two differing accounts of the origin of Imrahil's line, both in Unfinished Tales.
In the earlier account, the line was founded, according to "the tradition of [the] house", by Imrazôr the Númenórean and the Elven-lady Mithrellas, one of Nimrodel's Silvan companions. Imrazôr lived in Belfalas around T.A. 2000 and had two children: a boy Galador and a girl Gilmith. Shortly thereafter Mithrellas is said to have vanished in the night. Galador, according to this tradition, became the first Lord of Dol Amroth.
Although this account does not appear explicitly in The Lord of the Rings, it figures in the perception of Imrahil by the people of Minas Tirith: "Belike the old tales speak well; there is Elvish blood in the veins of that folk, for the people of Nimrodel dwelt in that land once long ago", as well as in the accolade from Legolas upon meeting Imrahil: "It is long since the people of Nimrodel left the woodlands of Lórien, and yet still one may see that not all sailed from Amroth's haven west over water." Tolkien began in fact to work out a genealogical table linking Galador with Imrahil, but he abandoned it after getting little farther than assigning dates to the mostly blank spaces in between.
The second account belongs, according to Christopher Tolkien to the late writings, undertaken well after the publication of The Lord of the Rings, when Tolkien turned to exploring the early history of Gondor and Rohan. Here Tolkien says that the title of "Prince" was given to the line of Dol Amroth by Elendil himself; this was the family that had led the original Númenórean colonization.
The Adrahil of Dol Amroth who fought with Calimehtar against the Wainriders in T.A. 1944 (predating both Imrazôr and the death of Amroth) probably also belongs to this version. Christopher adds to the note that while it is not impossible to forge some consistency between the two versions, they likely represent two independent accounts of the origin of the house.