Eons ago, before being forced to flee to a nether dimension in order to escape from Demogorge the God-Eater, the evil Elder God Chthon inscribed all of his dark mystical knowledge on indestructible parchments that were to serve as his permanent link to the Earthly plane.^[4][5] Those parchments later came to be known as the Darkhold and among the spells that they contained were both a spell that could create vampires and one that could destroy them.^[2]

Sometime before the Great Cataclysm, on the continent of Atlantis, the Darkhold spell was first used to create vampires.^[6] The first of them, Varnae,^[7] somehow either knew or learned that the Darkhold could also be used to destroy his kind.^[8]

In the late 12th century, the Darkhold scrolls came into the possession of the Catholic Church. The reigning Pope entrusted them to a young monk named Paolo Montesi who had only recently been appointed the curator of a little-known church library devoted to occult artifacts. Varnae learned that the Church had acquired the Darkhold but was also aware that they did not yet know that it could be used to destroy all vampires.^[9] However, Varnae probably did not know that the scroll that held the vampire-destroying spell was not then part of the Darkhold.

At some point, the Church learned that one of the indestructible parchments contained an incantation that could destroy all vampires. Paolo Montesi's son and successor, Giacomo Montesi, confirmed that that scroll had not been among those that his father had bound together and realized that it must have been taken eastward during the Hyborian Age. Giacomo sent expeditions to Tibet to try to obtain the missing scroll, but was assassinated by one of Varnae's human agents before a trade could be made with the Nine Wise Men of Kamar-Taj.^[10]

By the 15th century, when that scroll was finally brought to the Vatican and bound into the Darkhold, the long-sought-after spell had already become known as the "Montesi Formula." However, since the language in which it was written had not yet been fully deciphered, the spell could not be spoken. Before it could be translated, Dracula learned of its existence and forced a thief named Murgo to steal the Darkhold from the Vatican Library. Murgo succeeded, but was intercepted before he could deliver it to Dracula by the sorcerer Cagliostro, who killed him and took the Darkhold for himself.^[11]

In recent years, the Darkhold was obtained by Jack Russell, who gave it to Father Ramón Jóquez to translate.^[12] Father Jóquez became possessed by the spirit of the evil monk Aelfric and soon afterwards died during a battle between Aelfric's thrall, Dragonus, and the Werewolf by Night.^[13] However, the death of so learned a priest under such mysterious circumstances attracted the attention of Monsignore Giuseppe Montesi, who was then the curator of that secret wing of the Vatican Library. After receiving the notes that Father Jóquez had made, Montesi found a copy of the incantation among them and was finally able to use the spell.^[14]

After Montesi used the spell several times to destroy newly-created vampires, Dracula came to Vatican City to stop him. Dracula burned Montesi's copy of the spell and fatally injured the monk but, before dying, Montesi informed the vampire lord that, days earlier, he had mailed another copy of the incantation to Dracula's enemy, Quincy Harker.^[1]

Learning of this, Elianne Turac had Harker abducted in an attempt to get the Montesi Formula from him so she could use it against Dracula. However, despite being tortured, Harker insisted that he did not have it, and Turac was soon killed by Dracula.^[15]

Rachel van Helsing somehow acquired a copy of the Montesi Formula and had it secured within a castle on Pendarrow Hill that vampires could not enter. Dracula's daughter and nemesis, Lilith, learned of this and, unable to get the book containing the spell herself, secretly possessed Kitty Pryde and then manipulated the X-Men into stealing it. However, when "Kitty" began reciting the spell, she was prevented from finishing it by Nightcrawler, who had recognized the words as being from the Darkhold and believed that her soul would have been forfeit if she had completed the enchantment.^[16]

Later, Dracula sought out the Darkhold after learning that it could be used to grant him great power. However, his search led to him being opposed by Doctor Strange, Earth's Sorcerer Supreme, and his allies Hannibal King, Blade the Vampire-Slayer, Frank Drake and Wong. Using the power of the Darkhold, Doctor Strange was able to use the complete incantation to destroy Dracula and all vampires on Earth.^[2]

A later attempt by two Darkholders who had served Dracula to import a vampire from another reality succeeded but that vampire immediately disintegrated, proving that the Montesi Formula had erased the curse that allowed vampirism to exist in Earth's reality.^[3]