Boldog was a formidable Orc-captain of the host of Angband during the First Age. He was mentioned only in the The Lay of Leithian in The History of Middle-earth series Vol. III, The Lays of Beleriand published in 1985 by Christopher Tolkien.
- "Boldog he sent, but Boldog was slain:
Strange ye were not in Boldog's train. "
- —Passage in the "Lays of Beleriand"
As it is told in The Lays of Beleriand, Boldog was a formidable Orc-captain that was commanded by Morgoth to lead a host of Orcs on a great raid on the realm of Doriath and capture Lúthien, the daughter of its King Thingol and Queen Melian, the Maia. Boldog drives his host south over the highlands of Dorthonion and the through enchanted forest of Taur-nu-Fuin following the Orcs' Road of Haste into the Pass of Anach which cuts down the mountains of Ered Gorgoroth and across the shadowed valley of Nan Dungortheb. There where fell darkness meet the mists of the magic, protective List Melian, the Girdle of Melian, just east of the river Mindeb the Orc-host reached the border of Doriath. To meet the deadly threat posed by Boldog's invasion in force, Thingol musters his full might with his two great Captains, Beleg and Mablung. He leads the army of Sindarin Elves beyond the North March of Doriath. Thingol and Boldog meet in single combat in the midst of the battle. Thingol wielded his Dwarf-forged sword, Aranrúth, Boldog fought with an iron spear of some note that was later used by Mablung in the Hunting of the Wolf. Thingol slays Boldog, the Orc-host is utterly defeated and the remnants destroyed by being driven into Taur-nu-Fuin.
The Battle of the North March is the culminating battle of a series of attacks in Morgoth's campaign against Doriath following his victories in the Dagor Bragollach (Battle of Sudden Flame), the fourth of the great Battles of Beleriand that broke the Siege of Angband in the latter-half of the First Age.
Details of Boldog's Raid are scattered through numerous texts and versions of texts but not included in the Silmarillion as published by Christopher Tolkien, however, no aspect of it was in serious contradiction with the general story and its presence in such primary Middle-earth sources, as The Lay of Leithian was intended to be, argues for its continued inclusion. Boldog's independent command of a host of orcs with its formidable objectives indicates that he was several cuts above most other Orc Captains and Champions and it was thought elsewhere in the sources that he was some lesser order of the Maiar corrupted by Morgoth that took the form of an orc, which would explain his great power that surpassed that of most orcs of the time.