Ainagûl
Since the beginning of the first civilization, there has existed a line of wizards known as the “Ainagûl” (“holy sorcerer” in elvish). These wizards (the most powerful in the world) worship Corellon Larethian even though they are all human. Their purpose is to serve as liasion between the elves and humans, to help mankind handle their arcane power, and to curb the spread of evil. Over the past millenia, the Ainagûl have played an important role in many histories.
At any time, there is only one Ainagûl and this person serves until his/her death – though those who serve Corellon in this regard are granted an extended lifespan. At least one Ainagûl was removed from office by Corellon due to a shift to evil. The most recent Ainagûl was Elsa.
Occasionally, there will be a delay between the retiring of one Ainagûl and the ascension of the next. Usually this is in the case of a violent death as has happened at least nine times in history – including Elsa's death at the hands of the Dark Mage.
The first Ainagûl was Tsylaire, known as “The Wanderer” – who is now considered a demigod. When an Ainagûl dies without a replacement, he is sent back to the world to wander until he finds a suitable replacement. Most recently, Tsylaire was found by the Good Party in 11XX and he has (most likely) been wandering the world ever since.
Another prominent Ainagûl was Aurén Ilay, who served at the end of the second age – and was killed when Gruumsh dropped a meteor on the Dark Mage's castle.