Celepharn was the son of King Mallor of Arthedain.

He came to the throne in 1110 at the death of his father.

During his reign many Hobbits entered Eriador and the lands of Arnor. Most of these were Fallohides and Stoors, joining the Harfoots who had come earlier during the time of Celepharn's grandfather Beleg.

During Celepharn's rule the Southern Kingdom Gondor reached the height of its power, under Atanatar II Alcarin.

Celepharn died in 1191 T.A. and was succeeded by his son Celebrindor.