Bardiya either ruled the Achaemenid Empire for a few months in 522 BCE, or was impersonated by a magus called Gaumata (Old Persian: 𐎥𐎢𐎶𐎠𐎫 Gaumāta), whose name is given by Ctesias as Sphendadates (Old Persian: *Spantadātah; Ancient Greek: Σφενδαδάτης Sphendadátēs), until he was toppled by Darius the Great.

[9][10] The traditional view is based on several ancient sources, including the Behistun inscription[11] as well as Herodotus,[12] in Ctesias,[13] and Justin, although there are minor differences among them.

[14] According to Darius the Great, Cambyses II, after becoming king of Persia but before setting out for Egypt, killed Bardiya and kept this secret.

As a result of this dream Cambyses sent his trusted counselor Prexaspes from Egypt to Susa with the order to kill Smerdis" (i.e., Bardiya).

[15] Bardiya's death was not known to the people, and so in the spring of 522 BC, a usurper pretended to be him and proclaimed himself king on a mountain near the Persian town of Paishiyauvada.

[citation needed] The despotic rule of Cambyses, coupled with his long absence in Egypt, contributed to the fact that "the whole people, Persians, Medes and all the other nations," acknowledged the usurper, especially as he granted a tax relief for three years.

They surprised him at a castle in Nisa, home of the Nisean horses, and stabbed him to death in September 522 BC.

[citation needed] While the primary sources do not agree on the names and many other details, the three oldest surviving sources (Darius himself, Herodotus and Ctesias) all portray Gaumata/Pseudo-Smerdis/Sphendadates as an imposter who usurped the throne by posing as one of the sons of Cyrus the Great, i.e. as one of the brothers of Cambyses II.

In Darius' trilingual Behistun inscription, the prince being impersonated is named "Pirtiya" in Elamite, "Bardiya" in Old Persian, and "Barziya" in Akkadian.

Cambyses then readies his army to return to Susa, but while mounting his horse accidentally injures his thigh with the point of his sword.

The false Smerdis then continues to rule at Susa for some time, and gains support from everyone except the Persians when he grants a three-year military draft and tax exemption to the various peoples of the empire (3.67).

Meanwhile, Otanes, a nobleman of Persis, suspects that the king is not the brother of Cambyses, but rather the Smerdis whose ears Cyrus had commanded be cut off "for some grave reason" (3.69.6).

To confirm his suspicion, Otanes asks his daughter Phaidyme – who is a member of the harem and thus has access to the king – to check whether the man has ears.

The seven conspirators charge into the chambers of the king, and while five deal with the guards, Darius and Megabyzus kill the false Smerdis and a companion.

"[27] There are some implausibilities in the official story, e.g. the impostor resembled the real Bardiya so closely that most of his wives did not spot the difference, except for queen Phaidyme.

[10][23][30] In the next year, another person claiming to be Bardiya, named Vahyazdāta (Old Persian: 𐎺𐏃𐎹𐏀𐎭𐎠𐎫[31]) rose against Darius in eastern Persia and met with great success, but he was finally defeated, taken prisoner and executed.

"The impostor Magian Smerdis" is mentioned in the short story by Jorge Luis Borges, Tlön, Uqbar, Orbis Tertius.

He is the only historical character that the protagonist is able to recognize when discovering the article on the fictitious nation of Uqbar, and it is stated that his name has been invoked mainly as a metaphor.