The Children of Adam and Eve

Cambyses II (reigned 529-522 bc), king of Persia, son of Cyrus the Great,
whom he succeeded. In order to maintain control over the Persian Empire,
Cambyses had his Younger Brother, Smerdis (died about 523 bc), murdered.
He then led an expedition to conquer Egypt, the sole independent kingdom
in the Middle East after the conquest of Asia by his father. Cambyses
defeated Psamtik III, king of Egypt (reigned 526-525 bc), and succeeded in
conquering Egypt as far south as Nubia, but he failed in later attacks on
the Egyptian oasis of Ammonium (now Siwa) and in campaigns in Ethiopia.
During his absence in Egypt, a usurper, Gaumata (reigned 522 bc), claimed
to be Smerdis and seized the throne of Persia. The Death of Smerdis had
been kept secret; so Gaumata's claim was believed, and he was acknowledged
king throughout Persia for about seven months. Cambyses was on his way to
Persia to punish Gaumata when he either died by accident or committed
suicide. According to Herodotus, Cambyses II was a dissolute and inhuman
despot, prone to drunken or insane rages in which he committed
sacrilegious and cruel acts.