Rise of the Blades
Elves are relative newcomers to the continent of Khorvaire. Originally the elves were slaves to a race of giants on the southern continent of Xen’drik. They escaped to and founded a nation on the smaller continent of Aerenal.
Aerenal elves in Eberron practice a form of ancestor worship. On Aerenal, those elves deemed to be particularly beneficial to the race are magically revived as Undying. The lich-like beings are enchanted with positive energy instead of the negative energy that animates undead. The Undying act as counselors to the Aerenal elves.
Elves have occupied parts of Khorvaire sporadically, only recently forming their own nation there known as Valenar. Valenar elves hold different traditions from Aerenal elves, and stress bringing glory to their ancestors through combat. The Saarvalur elves of the Demon Wastes traverse the wastes in unique self-propelling vehicles, and utilize arcane weapons known as rauko carak, elvish for demon teeth.