Lore:Daughters of Coldharbour
A Daughter of Coldharbour is a female individual who has been granted vampirism through a ritual with the creator and patron deity of vampires, Molag Bal. The term comes from Coldharbour, the plane of Oblivion that Molag Bal lords over. Being pure-blooded, all Daughters of Coldharbour are also powerful Vampire Lords.
The first Daughter of Coldharbour can be roughly dated back to at least the early First Era. Lamae Beolfag was a Nedic virgin who was raped by Molag Bal. Legends recount that after the ordeal, Molag Bal shed a droplet of blood upon her brow and left her to die. During the night she passed into death, but as her funeral pyre was still burning she emerged as the first pure-blood vampire.
Since Lamae, a tradition developed among cults worshipping Molag Bal which dictated that women be offered to him on the 20th of Evening Star, his summoning day. Few survive the ordeal and those who do emerge as pure-blooded vampires. Being selected as an offering was considered to be an honor that was not rejected lightly.
Tyranny of the Sun
A prophecy written in the First Era by a Snow Elf named Vyrthur foretold that "The Blood of Coldharbour's Daughter will blind the eye of the Dragon." This referred to the Tyranny of the Sun, an ancient prophecy that foretells the eternal beclouding of the sun. This prophecy was later pursued by Lord Harkon, the progenitor on the Volkihar bloodline of vampires. He planned to sacrifice his daughter, Serana, in order to fulfill the prophecy. Disagreeing with his vision, Harkon's wife Valerica (also a Daughter of Coldharbour) took Serana and secretly fled far from his grasp, effectively putting an end to his plans. The prophecy was fulfilled, albeit temporarily, in 4E 201 by the Last Dragonborn using Serana's blood.