One of the thirteen men who fled into outlawry after the fall of Dorthonion in the Dagor Bragollach. Led by Barahir and his son Beren, this small band retreated into the highlands above their invaded homes, where they waged a secret war against Morgoth's forces for a time. At last, they were betrayed by Gorlim the Unhappy, and Hathaldir was slain with almost all the others (only Beren escaped death).

We know almost nothing else of Hathaldir's life, but it seems fair to assume from his title 'Hathaldir the Young' that he was the youngest of Barahir's outlaw companions.