Lost Army of Cambyses
The Lost Army of Cambyses was a military force sent by Cambyses II, emperor of the Archaemenid Empire and the conquerer of Egypt, to threaten the Oracle of Amun in Siwa.
At some point during its journey across the kingdom of Egypt, between 525 and 522 BCE, the army was waylaid by a sandstorm and lost to the desert. The army's existence shortly passed into story, and by 49 BCE was a legend known through Egypt.
Sometime around 38 BCE the Hidden One, Bayek of Siwa, travelled to the Seth-Anat tomb in the Desheret Desert–built within the remains of the Isu construct Qeneb.too Kah'Aiye–in order to investigate rumours of a curse spreading up from Thebes. Whilst travelling to the tomb, the Hidden One was attacked by the ghostly apparitions of undead soldiers who supposedly were a part of the Lost Army of Cambyses. Upon returning the source of the curse to its rightful place within the tomb, the undead soldiers returned to the sands.[1]