Long before he wrote The Lord of the Rings, J.R.R. Tolkien served in the British Army during the First World War. Upon his return to England he resumed writing, laying down the foundations of what would become Middle-Earth — an epic story that includes The Hobbit, The Lord of the Rings, and The Silmarillion. Now, a century after it was first written, Tolkien’s estate is publishing one of his earliest stories, Beren and Luthien, as a standalone book.

World War I had a profound impact on the young author. He joined the military along with several of his friends in 1915, and was deployed to Europe a year later, where he was part of the Battle of the Somme. That winter, Tolkien contracted trench fever, and learned that several of his closest friends had been killed in action. While overseas, many elements of what would become Tolkien’s world began to come together. Upon returning home, he began to set down some of these stories to paper, translating some of his experiences into his fantasy epic. One of the first stories was The Tale of Tinúviel, a romance between a mortal named Beren and an elf, Lúthien, which Tolkien completed in 1917.

Tolkien was inspired to write the piece after a walk with his wife, Edith, who became the basis for Lúthien. The story followed Beren, a survivor of a group that had fought Morgoth during Middle-Earth’s First Age (thousands of years before the events of Lord of the Rings). After fleeing, he entered the elvish realm of Doriath, where he meets the elvish princess Lúthien, falling in love at first sight. Disapproving of the romance, her father, an elf king named Thingol gives Beren an impossible task that must be accomplished: retrieving a Simaril jewel from Morgoth. Beren set off to retrieve the gem, encountering Orcs and Sauron.

The story of Beren and Lúthien is particularly important to Middle-Earth

The story of Beren and Lúthien is particularly important to Tolkien’s Middle-Earth saga: it was a major union between humans and elves, which would ultimately form the basis for the union of Aragorn and Arwen, two major figures in The Lord of the Rings. The story was also deeply personal to Tolkien: the grave that he and his wife share is marked with the names Beren and Lúthien.

Tolkien continued to tinker with the story long after it was written. He began to adapt it as an epic poem titled the "The Lay of Leithian," but ultimately never completed it. However, the story was later referenced in The Lord of the Rings, and several versions of the story were later included in The Silmarillion in 1977, and The Book of Lost Tales in 1984.

The Tolkien Estate, under the direction of Tolkien’s son Christopher, has released a number of works based off of Tolkien’s earlier manuscripts and notes, such as The Story of Kullervo, Beowulf, The Fall of Arthur, The Children of Húrin, and The Legend of Sigurd and Gudrún.

Beren and Luthien will be released in May of 2017.