Hendalacon => essë – father name (Stormy Eyes).
Aváru => amilessë – mother name (Unwilling; Stubborn).
Altaha => epessë – (Great Rage [q.])

Born a few years after Fëanaro created the Silmarils. He became friends with Fanuiamarth Oropherion and Morifinwë in childhood. He was his father’s favourite, but his mother, Valatindë, frowned upon his many faults.

A staunch follower of Fëanaro, Hendalacon followed the High Lord to Alqualondë, with his friends, Fanuiamarth and Morifinwë. Due to his stubborn, unbending streak, he was accompanied by his father, Mórivo. They participated willingly in the kinslaying, for Mórivo cared not for the Teleri after they refused them their ships. Mórivo was slain in the ensuing battle and Hendalacon was wounded and left for the dead by his friends as they sailed away towards the north.

Hendalacon was helped by an elf from the host of Fingolfin and taken to Araman. But he arrived too late and missed sailing with Fëanaro’s ships. He passed over Helcaraxë with Fingolfin’s host, but parted with their company to join Morifinwë (Caranthir in Sindarin now) in his abode near the Lake Helevorn in Thargelion.

Caranthir bestowed upon him his epessë: Altaha, because of his tendency to fly into a wrath at the slightest provocation.

In the Dagor Bragollach, Morgoth’s Orcs took the mountain forts on Mount Rerir, and defiled Lake Helevorn, then they scattered south through Thargelion into East Beleriand. Caranthir and his brother, Amrod, accompanied by Altaha fled to Amon Ereb, where they built defences. From there they slowly freed East Beleriand of the Orcs, aided by the Laiquendi, while Maglor and Maedhros held the northern border.

Altaha helped to control the Dwarven traffic through his realms and thus gained great wealth. He was haughty in dealing with the Naugrim, further perpetuating the dislike between the Noldor and the Dwarves. After he helped Caranthir to rescue the Edain lady, Haleth and her people, the Haladin, as they were besieged by Orcs he saw the valour of Men. When the Haladin refused Caranthir’s offer of free lands in the North, they incurred Altaha’s wrath.

He never liked them after that and refused to have any dealings with them. When The Folk of Ulfang swore fealty to Caranthir, and was allowed to settle in Thargelion, Altaha fought against Caranthir.

After Caranthir perished (FA 507) along with his brothers Celegorm and Curufin during the Second Kinslaying — the attack by the Sons of Fëanor on Menegroth to recover the Silmarils from Elven King Dior of Doriath, Altaha remained with Amrod.

When Amrod is slain (FA 538), during the third kinslaying, Altaha joins Maedhros’ company.

Altaha dies in the War of Wrath.