[Morgul Queen]

I recall reading an essay on Elven twins about a year ago, I'll try and dig up the URL, but it talked about how twins in Tolkien are essentially one person with a divergant fate. Amrad and Amras were the first example. One, Amras, was actually supposed to die at Losgar when the ships burned - he was to be trapped inside one, but was rescued - and Amrod was to die at the mouths of the sirion. However, this fate was avoided and they both were killed during the Third Kinslaying.

Originally, Elwing and Earendil had only one child, Elrond, who chose to be Mortal, but again the divergence of the fates for this child resulted ina twin being born, Elros, who chose to be Mortal, rather than Elrond, who, with the appearance of a twin, chose to be of the Eldar, thus accomodating both Fates.

Confused? I'll find the URL, the original essay is a lot clearer, this is just paraphrased from what I remember of it, there's a lot more info and detail.