Tar-Ciryatan (1634 - 2035 S.A., 1869 - 2029 S.A.), or Ar-Balkumagân in Adûnaic was the 12th ruler of Númenor. He succeeded his father, Tar-Minastir, as King.
Tar-Ciryatan was a great ship builder, and he waged war upon Middle-earth, bringing its treasures back to Númenor. His name literally means "Ship-builder".
He abdicated in 2029 S.A. and was succeeded by his son, Tar-Atanamir. He is also referred to as the father of the Witch-King of Angmar, but this is not considered to be a part of the Middle-Earth canon.