He is probably the oldest Eladrin still in Middle-Earth. He was the keeper of the seven rings of power that enabled the Eladrin, Elves, Humans, Dragonborn, and Dwarves of old to keep the forces of the Dark Gods at bay.
Cirdan and his family held the two Eladrin rings of power after the others were lost during the war with the Drow.
The fate of the other rings is unknown. Cirdan and his son Prince Olowe have been searching all of Middle-earth to find the other rings.
Cirdan is also known as Nowe.