Chalice (Assassin's Creed)
The Chalice was an artifact that featured in Assassin's Creed: Altair's Chronicles.
This item was a sacred object that was known between the Assassin's and the Knights Templar. It was known to have the power to unite the nations of one faction under one flag. The user thus had the power of uniting the faction under their rule which made it a potent power for either the Crusaders or the Saracens. The discovery of the Chalice would have meant total victory for one side in the Third Crusade. Thus it was deemed too powerful to be left alone in the hands of men which meant that it had to be found and destroyed.
The assassin Altaïr was sent to achieve this goal.