The Hidden Ones

The Hidden Ones were a precursor incarnation of the Assassin Brotherhood operating throughout the Roman Empire. The first organized and developed Brotherhood in its own right, the Hidden Ones were founded in Egypt, 47 BCE, by Bayek and his wife, Aya, with the stated aim of working from the shadows to ensure that those who would seek to control humanity's free will would die.

In 1050 CE, under the leadership of Hassan-i Sabbāh, they founded a sovereign state in their own right, becoming a more public organization that eventually became known as the Assassin Brotherhood.

History
Bayek, the local protector of the Siwa Oasis in Egypt, went hunting with his young son Khemu in order to train him to become his eventual successor. However, when they discovered that Khemu's friend Chenzira was kidnapped by members of the Order of the Ancients, a group that would later evolve into the Templar Order, Bayek ordered his son to run home and proceeded to confront the men. Unfortunately, Bayek was overpowered by them and taken to an Siwa Vault hidden beneath the Temple of Amun, where they pushed him for information about how to open it, believing that it involved using an Apples of Eden. In order to force him to cooperate, the masked men had kidnapped Khemu and threatened to kill him if Bayek did not provide them with the information.