[Formendacil]

Originally Posted by Huinesoron

So. Two of these are children of an elf and a mortal (Eldarion, Galador). Two of them are the last named members of their lines (Eldarion, Elboron). All four of them are princes, but that doesn't seem specific enough.

Two of them are the first heir to a line - Eldarion to the house of Telcontar, Elboron to the Princeship of Ithilien. Galador is the founder of Dol Amroth, but is also the second known Prince of Belfalas (after his father). So are they all the second known to hold their title in a specific line?

Let's see what we can do with Eldacar. Hmm... since Isildur claimed the title of High King, Eldacar of Arnor (despite being much less exciting than his later southern cousin) was technically the second King of Arnor, after Valandil. So one possible answer is that they're the second known holder of/first known heir to their various titles.

Another answer, this time looking at Eldacar of Gondor, is that they're all children of two races. Eldarion and Galador are Elf-Man crosses; Elboron is Gondor/Rohan; and Eldacar of Gondor is son of a Gondorian father and a Northman mother (actually the same as Elboron, give or take a major migration). So that could also be what you're thinking of.

hS

Your last formulation is closest, though I have a more specific fact in mind--i.e. Earendil would NOT share it.