He succeeded his father to the throne in T.A. 158. Little is known is about his reign, only that it was a peaceful one.
He was succeeded by his son Eärendil in T.A. 238.
A much earlier Cemendur (b. S.A. 575) was a descendant of Elros, and the son of Axantur. He had two children: a daughter Írildë, and a son Hallatan. Hallatan was the father of Hallacar, the husband of Tar-Ancalimë.