Haldir was the eldest son of Halmir and a Chieftain of the Folk of Haleth during the First Age. He married Glóredhel of the House of Hador; her younger brother, Gador the Tall, married Haldir's sister, Hareth. Haldir and Glóredhel had a son, Handir; their grandson was Brandir the Lame.
As Hador's son-in-law, Haldir fostered Húrin and Huor in Brethil. Together they took part in an ambush of Orcs who came from the Pass of Sirion soon after the Dagor Bragollach; the Orcs were destroyed by Halmir's forces.
When his father prepared the Folk of Brethil to join the Union of Maedhros, Haldir obeyed Fingon's summons. With his brother Hundar, he led many warriors to the Nirnaeth Arneodiad, where they joined forces with Hurin, now Lord of Dor-lómin. Haldir and most of his men were slain in battle, and only three men returned to Brethil. Glóredhel, learning of the news, died of her grief. The Folk of Haleth were thereafter ruled by their son Handir.
Who Are the Haladin?
The Haladin were the second of the three peoples of the Edain to cross the Blue Mountains and enter into Beleriand. For awhile they dwelt in Thargelion, but were later led into the west by Haleth, where they founded homes in the Forest of Brethil.