Buckingham Palace vault

The Buckingham Palace Vault is a First Civilization vault located beneath Buckingham Palace in London. Until 2015, the vault housed one of the Shrouds of Eden, a Piece of Eden capable of restoration.

At some point in the early 18th century, the British Brotherhood of Assassins hid the Shroud of Eden in the vault to keep it hidden from the British Templars, who were gaining control over London. The artifact remained hidden for over a century, until 1868, when the Grand Master Crawford Starrick sought to obtain the location of the artifact with the help of the occultist Lucy Thorne.

The Assassins Henry Green and Evie Frye also worked to find the location of the artifact, finding clues in the mansion of the late Master Assassin Edward Kenway. Using these clues, Evie located the key to the vault in St Paul's Cathedral.

After dismantling Starrick's organization, Evie and her twin brother Jacob Frye attended a ball at Buckingham Palace, where Starrick planned to kill Queen Victoria and the members of Parliament. Starrick stole the key from Evie, and used it to open the vault and obtain the Shroud. After a long battle between Starrick and the Frye twins, the Assassins managed to kill the Grand Master, and chose to leave the artifact in the vault.

In October 2015, the Assassins and Abstergo Industries located the vault through the genetic memories of the Frye twins and infiltrated it to obtain the artifact. During a fight between the Assassins and the Templars, Rebecca Crane was wounded and the Assassins were forced to flee, allowing the Templars to take the Shroud.

Reference

 * Assassin's Creed: Syndicate