Narn i Chîn Húrin
Narn i Chîn Húrin (Sindarin for "Tale of the Children of Húrin"), also called "The Narn", is a long story of all that happened to Húrin and his children Túrin and Nienor, after Húrin was cursed by Morgoth.
The story elaborates on what is told of these characters in the published Silmarillion, starting with the childhood of Túrin, continuing through the captivity of his father in the Nirnaeth Arnoediad ("Battle of Unnumbered TEars"), and Túrin's exile in Doriath, to Túrin's time in Nargothrond and ending with his suicide after having slain Glaurung.
The story has some inconsistencies when compared with The Silmarillion, and at points there are gaps and multiple versions. This is because Tolkien never finished the story during his lifetime, and his son Christopher Tolkien had to choose from all the work to create a consistent narrative for The Silmarillion.
The story of the Narn continues in the Later Narn, which is published in Unfinished Tales, and in the "Wanderings of Húrin", a text which was found to be too different in style from rest of The Silmarillion, but which continues the Narn past Túrin's death and ends with Húrin's eventual release and the bad deeds which follow him. This story was finally published in The War of the Jewels, a volume of The History of Middle-earth series.
Note that the title of the Narn is given as Narn i Hîn Húrin in the published Silmarillion and Unfinished Tales. This was an editorial decision by Christopher Tolkien which he later regretted, done only to prevent people from pronouncing Chîn like the English "chin".
