Lumen Histoire is located in a secret underground room in Fairy Tail's original building. This secret is only known by Fairy Tail's Guild Master and is passed on to the new Master successively. Precht showed it to Makarov when he became Master. Years later, Makarov showed it to Gildarts Clive when he told him that he wanted him to be next Master of Fairy Tail. According to Ivan Dreyar, Lumen Histoire is Fairy Tail's darkness, while according to Mavis Vermilion, it is Fairy Tail's light.
Later, it is revealed that Lumen Histoire is in fact the body of Mavis Vermilion encased in a crystal. Makarov also calls it the "ultimate weapon" of Fairy Tail.
In X781, the Albareth Empire attempted to mount an invasion of the continent of Ishgar with their intention being to capture Lumen Histoire, but was stopped by the Magic Council's firing of Etherion. However, the empire never relinquished their intent to capture the artifact, and Makarov expected them to attempt invasion once again, especially with Magic Council being crippled after the Massacre at Era and the Fairy Tail-Tartaros War, which left Etherion and Face rendered useless.