The Lay of Leithian is an unfinished poem written by J. R. R. Tolkien. It tells the Tale of Beren and Lúthien, the story of the love of the mortal Man Beren and the immortal Elf maiden Lúthien. The poem consists of over 4200 verses. It was published after Tolkien's death in The Lays of Beleriand. Its precedents are found in the Welsh tale of Culhwch and Olwen in the manuscripts, the Red Book of Hergest and the earlier White Book of Rhydderch.
Leithian is a word in one of Tolkien's invented languages which derives from leithia, meaning "release". The title bears a strong resemblance to the word Leithien, the name for England in earlier versions of Tolkien's legendarium.
The author translated the title as release from bondage, without making explicit who was released from what form of bondage. There are, accordingly, several possible interpretations.
One likely meaning of the title might be found at one of the key moments in the poem, the point at which one of the Silmarils, the magical gems of Fëanor, is cut from the crown of Morgoth by Beren:
Behold! the hope of Elvenland
the fire of Fëanor, Light of Morn
before the sun and moon were born,
thus out of bondage came at last,
from iron to mortal hand it passed.
This moment is also central to the overarching story-line of The Silmarillion, in which the gem is used to bring hope to the scattered peoples of Middle-earth and is ultimately set in the heavens by the mariner Eärendil as a sign of their coming salvation.
The name of the poem is therefore likely an attempt to underscore the importance of the Lay relative to other tales from the first age. Though honor, bravery and vengeance drive the Elven hosts forward to war with Morgoth, it is only love that can overcome all obstacles to wrest a Silmaril from his crown.
Another interpretation is that Lúthien is released from the bonds of the Eldar to the physical world (the world that is, Arda). In The Silmarillion it is said that Lúthien alone among the elves has died indeed, and left the world. By contrast, it is basic to Tolkien's Christian and Catholic conception of Arda that Men, the younger children of Ilúvatar (God), by means of the Gift of Men (death) are able to escape the confines of the world. Note the comfort offered by the mortal King Elessar to his elvish bride Arwen as his death approaches: "we are not bound forever to the circles of the world."
Indeed, the theme of release from imprisonment runs like a thread throughout the story: Lúthien's escape from Doriath, her release from Nargothrond with the aid of Huan, Beren's release from Gaurhoth Isle. In every instance it is love that is the liberating factor: Lúthien's love for Beren drives her on to find some escape from imprisonment by her father, Huan's love for Lúthien is what frees her from Nargothrond, Beren's rescue by Lúthien. One could hazard an interpretation of the title as being suggestive of the immense power of love.
Hence, the theme might find an echo in line 2978 of Canto X, spoken by Beren:
Thy love me drew from bondage drear,
but never to that outer fear,
that darkest mansion of all dread,
shall thy most blissful light be led.
After the ruin of his land in the Battle of Sudden Flame the Man Beren fled into the elvish realm of Doriath. There he met the Elf-maiden Lúthien and they fell in love with each other. Thingol, the father of Lúthien, did not want his daughter to marry a mortal man. Therefore, he asked Beren for a Silmaril, one of the hallowed jewels which the Dark Lord Morgoth had stolen from the Elves, as the bride price. With the help of Huan and Finrod Felagund, Beren and Lúthien defeated Sauron and came to Angband, where they stole a Silmaril from Morgoth's crown. The unfinished poem ends when they encounter the wolf Carcharoth at the gate of Angband.
Besides the main story the poem also tells of many events which happened before, like the meeting of Thingol and Melian, the oath of Fëanor, the return of the Noldor, the war of Beleriand and the duel of Fingolfin and Morgoth.
The poem consists of over 4200 lines of iambic tetrameter. It is written in rhyming couplets.
Tolkien worked on The Lay of Leithian from the summer of 1925 until September 1931, when he abandoned it with only thirteen of the seventeen planned cantos completed. During the composition he made many amendments of the already existing parts of the poem, partially based on the criticism of his friend C. S. Lewis who had read the poem in 1929. In the 1950s, after the publishing of The Lord of the Rings, he resumed working on the poem, of which he rewrote many passages, particularly of the second canto which was expanded and split into two. Nevertheless, the poem never reached a complete or definite form.
In 1937 Tolkien sent the current version of The Lay of Leithian together with a prose version of the yet unfinished part of the poem to his publisher Allen & Unwin who had asked for further material of his fictional world after the success of The Hobbit. As Tolkien did not add any further information on the text the reader who was given it believed the poem to be an attempt to retell the prose version, which he thought to be a Celtic tale. Despite praising the prose he criticized the poem wherefore it was rejected. In 1985 the poem was published posthumously in The Lays of Beleriand, the third volume of The History of Middle-earth. The two versions of the poem are given independently, and the development of them is commented on in detail by Christopher Tolkien.The Austrian band Summoning, known for its Tolkien-themed lyrics, released a song titled "Menegroth" which is a setting of part of the Lay.