In the Middle-earth legendarium of J. R. R. Tolkien, Húrin was a hero of Men during the First Age, said to be the greatest warrior of both the Edain and all the other Men in Middle-earth. Húrin Thalion (Sindarin for The Steadfast) was the elder son of Galdor the Tall of the House of Hador and Hareth of the Haladin, and he had a younger brother Huor.
...[Húrin] was shorter in stature than other men of his kin; in this he took after his mother's people, but in all else he was like Hador his grandfather, fair of face and golden-haired, strong in body and fiery of mood. But the fire in him burned steadily, and he had great endurance of will. Of all Men of the North he knew most of the counsels of the Noldor.
In the Year of the Sun 458 of the First Age Huor and Húrin lived with their uncle Haldir in the forest of Brethil, when they joined a war party against the Orcs. The brothers ended up in the Vale of Sirion, and were cut off from their company and chased by Orcs. The Vala of Waters Ulmo caused a mist to arise from the river, and the brothers escaped into Dimbar. There two Eagles picked them up, and brought them to Gondolin. King Turgon welcomed the brothers, remembering Ulmo's prophecy that the House of Hador would aid Gondolin in their time of greatest need. Turgon would them remain as he grew to love them, but the brothers wished to return to their kin. They swore an oath to keep Gondolin secret, and Eagles brought them back to Dor-lómin.
In 462 Morgoth assailed Hithlum, and Húrin's father Galdor fell defending the Barad Eithel. Húrin chased the Orcs away with heavy slaughter over the plains of Anfauglith, for "there was a fire in him that made the sword hot in his hand". He then took the Lordship of his people and their fief of Dor-lómin in Hithlum being only 21 years old.
Soon he married Morwen Edhelwen of the House of Bëor, and in 464 their son Túrin was born. A daughter Lalaith followed, but she died aged three years by a plague sent from Angband. His house was in the south of the land, near Amon Darthir and the stream of Nen Lalaith; but "Húrin was often long away from home with the host of Fingon that guarded Hithlum's eastern borders, and when he returned his quick speech, full of strange words and jests and half-meanings, bewildered Túrin". After the death of his daughter Húrin "Mourned openly, and he took up his harp and would make a song of lamentation; but he could not, and he broke his harp, and going out he lifted up his hand towards the North, crying: 'Marrer of Middle-earth, would that I might see thee face to face, and mar thee as my lord Fingolfin did!'"
When the Union of Maedhros prepared to battle with Morgoth, Húrin feared little that they will be defeated. In 472, in the Nírnaeth Arnoediad, Húrin fought alongside Huor and the Folk of Hador, and in the midst of battle he met again with Turgon. When the battle was lost, Húrin and Huor took a stand fighting off the Orcs, allowing Turgon to escape. Huor and all the Men of Dor-lómin were slain, but Húrin fought with his battle-axe until his axe melted, he was buried under a mountain of slain Orcs and Trolls. Húrin was then bound alive by Gothmog Lord of Balrogs and brought captive to Angband.
Morgoth then tried to daunt Húrin and get knowledge of Turgon's dwelling, tormenting him and tempting with freedom or high rank in Morgoth's army. Húrin defied, but Morgoth took him to Haudh-en-Ndengin, cursed along with his kin. Húrin still would not surrender, and was placed high on the peaks of Thangorodrim, either chained or magically immobilized in a seat. Through the power of Morgoth, he could see and hear from the seat all the evils that later befell his son Túrin and second daughter Nienor, who was born while he was a captive. But he saw only those things that Morgoth wished to reveal, lessening their good deeds and casting shadow on the counsels of Thingol and the Haladin. Húrin was thus embittered even more by the way his children, both under the spells of Glaurung, came to get married and later commit suicide.
After twenty eight years of imprisonment and the death of his children, Húrin was released by Morgoth. "He had grown grim to look upon: his hair and beard were white and long, but there was a fell light in his eyes. He walked unbowed, and yet carried a great black staff; but he was girt with a sword." He was brought to his old homelands in Hithlum, but the Easterlings living there at first did not recognize him and later feared him, believing he served their evil lord Morgoth. The House of Hador had been destroyed, and those who remained as slaves or outlaws held him in suspicion and fear.
Seven outlaws under Asgon joined Húrin, and together they went to the Vale of Sirion. Húrin abandoned his followers and sought the entrance to Gondolin, but the Hidden City was closed, and Turgon at first did not wish to allow him in. Húrin cried out against Turgon, thus revealing the location of Gondolin to Morgoth's spies, and then left. Only after he had left did Turgon have a change of heart and send Eagles to fetch him, but they came too late and did not find him.
Húrin continued to the forest of Brethil where his son and daughter had died, and met his wife Morwen there at their grave at Cabed-en-Aras, just before she, too, died. In anger and despair he sought out the Folk of Haleth, blaming them for the death of his wife and children, and caused a revolt that killed the last Haladin. For Hardang the Chieftain of Brethil feared and dishonoured Húrin, imprisoning and trying to kill him. Húrin's cause was defended by Manthor, and they managed to set the Folk of Brethil against Hardang and slay him. But Manthor himself was killed, and guessed the will of Húrin: "Was not this your true errand, Man of the North: to bring ruin upon us to weigh against thine own?"
Húrin met up again with the outlaws, and together they went to Nargothrond, where Húrin killed the Petty-dwarf Mîm who had claimed the treasure of Glaurung, earning a curse on the gold. Húrin and his outlaws brought the treasure, including the Nauglamír, to Doriath, insulting Thingol by giving it as a fee for his 'good care' of Húrin's kin. Húrin thus brought a curse on Doriath as well, eventually leading to its downfall.
Melian's kind words managed to break through to Húrin's clouded mind, and Húrin finally saw that all his deeds had only aided Morgoth. A broken man, he was rumoured to have cast himself in the sea and killed himself. That was the end of Húrin, who had been known as the "mightiest of the warriors of mortal men".
Húrin's horse that he rode to the Nírnaeth Arnoediad was called Arroch, 'Noble horse'.
This article includes information from the expanded Narn i Chîn Húrin and The Wanderings of Húrin: the account in the published The Silmarillion, according to which Húrin himself buried Morwen and brought Nauglamír to Thingol, has been significantly edited for publication.
In early versions of Tolkien's mythology (see: The History of Middle-earth) his name was Úrin or Úrinthalion, and also Thalion Erithámrod 'the Unbending'. For the question of etymology of his later name Húrin see House of Hador.