This Staff passed into the hands of the first disciple of Jesus, Peter, who helped to establish Christianity and became the first Pope. It is assumed that over the next fourteen centuries the Staff circulated through the hands of the Roman Popes, until it was seized by Rodrigo Borgia, who had became Pope Alexander VI in 1492 so that he could use the Staff to gain access to the Vatican Vault.
On 28 December 1499, the Italian Assassin Ezio Auditore da Firenze infiltrated the Sistine Chapel to confront Rodrigo, and a fight ensued, during which Rodrigo wielded the Staff as a spear against Ezio. Eventually, Ezio defeated Rodrigo and used the Staff (combined with his Apple of Eden) to enter the Vault.
When leaving the Vault, Ezio tried to remove the Staff from the center of the room where it was secured within the Vault's antechamber floor. Upon doing so, Ezio activated machinery that made the Staff descend underground, despite Ezio's efforts to retrieve it.
Designed to control men's minds and bodies, the Papal Staff held a cradle in its headpiece where an Apple of Eden could be placed, in order to enhance its mind control effects. This combination of two Pieces of Eden could also be used to open the door to the Vatican Vault.
The Staff's bottom end was sharpened, and could be wielded as a spear in combat. The artifact also granted the possessor the ability to conceal their presence entirely, and the ability of levitation; though whether these were physical effects or simply manipulations of the viewers' perceptions remains unknown.