Although the Undying Court are the spiritual leaders of Aerenal, they also rely on a living administrative body lead by a pair of elven siblings, called the Sibling Kings. The pair must consist of one woman and one man, and if either dies, the Court selects and inducts a new pair. The current pair are Lady Tezaera and Lord Balaereth, and are based out of Shae Cairdal in the center of the country. The Cairdal Blades are their elite bodyguards, and always have a few elves who bear the Mark of Shadow, extremely rare since House Phiarlan left the island.