Easterlings (First Age)
Some of them, like Bór, entered the service of the House of Feanor and fought with Maedhros in the Nirnaeth Arnoediad. Others, like Ulfang and his sons, were for a part secretly in league with Morgoth and betrayed Caranthir resulting in the defeat.
The Easterlings were betrayed by their lord Morgoth, and confined to Hithlum in the latter years of the First Age, where they enslaved the Elves and remaining Edain. Some, like Brodda, intermarried with the Edain.
Sons of Bór
Bór was a leader of Men who came into Lothlann, Beleriand, in the year 463. His sons were Borlach, Borlad and Borthand. Bór was welcomed by Maedhros, who gave him and his followers land north of the March of Maedhros, and south of it. Bór and his sons swore allegiance to Maedhros, and remained faithful, though he was told by Morgoth to betray the banner of Caranthir. All of them were wiped out during the Nirnaeth Arnoediad.
Sons of Ulfang "the Accursed"
Ulfang also came in Lothlann, Beleriand, in 463, shortly after Bór. He was the father of Ulfast, Ulwarth, and Uldor. Ulfang was welcomed by the sons of Fëanor, and he and his sons swore allegiance to Caranthir. They were given lands to dwell in the north and south of the March of Maedhros. Ulfang and his sons were secretly in the employ of Morgoth, and betrayed the Eldar and Edain during the Nirnaeth Arnoediad in what is now known as the Treachery of Men.
- ↑ Karen Wynn Fonstad suggests that the Easterlings of the First Age were related to the Easterlings of the Third Age; during the deluge of Beleriand they fled to Rhûn and were the ancestors of the Easterlings as they appear in The Lord of the Rings. Cf. Karen Wynn Fonstad (1991), The Atlas of Middle-earth, p. 40-41