The Unofficial Elder Scrolls RPG: Arcane Arts - Wonders of the Ayleids (3rd Edition)

From the introduction: The Ayleid people, otherwise known as the Heartland High Elves or Wild Elves, have a very diverse history and culture that spans centuries. They were a cruel race, their culture rife with daedra worship and slave torturing. However, they are most known for their highly advanced magic, the likes and magnitude of which hasn’t been present on Tamriel since their downfall.