In Tolkien's book The Silmarillion, Hurin was the head of the house of Hador at the time of the Nirnaeth Arnoediad. He was transported to Gondolin by the eagles along with Huor, but was allowed to return to his people. His forces fought alongside the elves, and a valiant rearguard action by them along the river Sirion cost Morgoth's forces dear and enabled Turgon's army to escape back to Gondolin. Sadly, Hurin was captured by Morgoth, whereupon he was transported back to Angband and chained to a chair to watch the tragedy which would befall his loved ones, who were cursed. Morgoth also worked foul sorcery upon him to distort his will and perceptions.
He saw the tragic events which afflicted his children Turin and Nienor, and, when finally freed by Morgoth, went forth to confirm the truth of what he saw. He met his wife Morwen one last time and learnt from her what had befallen; after which he fell into a state of madness in which he returned to the gates of Gondolin and cried out, revealing its location to Morgoth. He then went to Nargothrond, slew Mim the petty dwarf and retrieved the Nauglamir, which for some Morgoth-encursed reason he gave to Elwe, triggering the events which led to the fall of Doriath.
Pronounced HOO-rin. It should have a rightward-slanting dash over the "U", but I don't think you can put those on Urban Dictionary.