What was the name of the Assassin precursor organization founded by Bayek and Aya?

The Hidden Ones was the Assassin precursor organization founded by Bayek and Aya.

In Assassin's Creed Origins, Bayek and Aya establish the Hidden Ones after confronting the Order of the Ancients, a secret organization seeking political control in Ptolemaic Egypt. The Hidden Ones operate from concealed bases and use covert methods to protect ordinary people from abusive power.

The organization is historically earlier than the medieval Assassin Brotherhood seen in the first Assassin's Creed. Origins therefore functions as an origin story for the series' central creed, symbols, methods, and conflict with the Templars' predecessors.

A common mix-up is answering “Order of the Ancients.” That is the opposing organization in Origins, not Bayek and Aya's group. The later Assassin Brotherhood develops from the Hidden Ones as the organization and its ideals continue through subsequent centuries.