(Σμέρδις), the son of Cyrus, the founder of the Persian empire, accompanied his elder brother Cambyses to Egypt, but was sent back by the latter to Susa, because he was the only one of all the Persians who was strong enough to bend the bow which the king of the Ethiopians had sent to the Persian monarch. Shortly after-wards Cambyses dreamt that a messenger came to him from Persia, announcing that his brother was seated on the royal throne with his head reaching to the skies. Alarmed at this dream portending his brother's greatness, he sent a confidential servant named Prexaspes to Susa with express orders to put Smerdis to death. Prexaspes fulfilled his commission, murdered Smerdis secretly, and buried him with his own hands. Among the few persons who were privy to the murder was Patizeithes, a Magian, who had been left by Cambyses in charge of his palace and treasures. This person had a brother who bore the same name as the deceased prince, and strongly resembled him in person; and as most of the Persians believed Smerdis to be alive, and were disgusted and alarmed at the frantic tyranny of Cambyses, he resolved to proclaim this brother as king, representing him as the younger son of the great Cyrus. Cambyses hear 1 of the revolt in Syria, but he died of an accidental wound in the thigh, as he was mounting his horse to march against the usurper. Before his death he assembled the Persians, confessed to them that he had murdered his brother, and conjured them not to submit to a Mede and a Magian. But the words of Cambyses did not meet with much belief; and Prexaspes positively denied that he had put Smerdis to death, as it would not have been safe for him to have admitted that he had murdered one of the sons of Cyrus. The false Smerdis was thus acknowledged as king by the Persians, and, with the assistance of his brother Patizeithes, reigned for seven months without opposition. But the leading Persian nobles seem never to have been quite free from suspicion ; and this suspicion was increased by the king never inviting any of them to the palace and never appearing in public, as well as by his wish to conciliate the subject nations by granting them exemption from taxes and military service for three years. Among the nobles who entertained these suspicions was Otanes, whose daughter Phaedima had been one of the wives of Cambyses, and had been transferred together with the rest of the royal harem to his successor. The new king had some years before been deprived of his ears by Cyrus for some offence; and Otanes now persuaded his daughter to ascertain whether her master had really lost his ears. Phaedima undertook the dangerous task, ascertained that the king had no ears, and communicated the decisive information to her father. Otanes thereupon organized a conspiracy to get rid of the pretender, and in conjunction with six other noble Persians, succeeded in forcing his way into the palace, where they slew the false Smerdis and his brother Patizeithes in the eighth month of their reign, B. C. 521. Their death was followed by a general massacre of the Magians. The events which followed, the dissension between the seven conspirators respecting the form of government which should be established in Persia, and the accession of Dareius son of Hystaspes. are related elsewhere. [DAREIUS.] (Hdt. 3.30, 61_79.)

The account of Ctesias is very different from that of Herodotus. Ctesias gives the name of Tanyoxarces to the brother of Cambyses, and relates that Cyrus had left him satrap of Bactria and the surrounding countries. He further says, that a Magian of the name of Spendadates accused Tanyoxarces to the king of an intention to revolt, in consequence of which he was secretly put to death, but in order to deceive Amytis, the mother of Cambyses, Spendadates, who bore a striking resemblance to the deceased prince, was ordered to personate him, and governed Bactria for five years as if he were the real brother of Cambyses. The fraud was at length discovered by Amytis, who put an end to her own life by poison, after imprecating curses on Cambyses. The king died soon after of a wound at Babylon, whereupon Spendadates mounted the throne, and reigned for a time under the name of Tanyoxarces. His imposture, however, was at length discovered, and he was put to death in his palace by seven noble Persians, who had conspired against him (Ctesias, Pers. cc. 8, 10-14). Xenophon (Xen. Cyrop. 8.7.11) calls the brother of Cambyses Tanaoxares, which is merely another form of the name in Ctesias, but assigns to him the satrapies of the Medes, Armenians, and Cadusii. On the other hand, the names given to him by Aeschylus (Prom. 780), and Justin (1.9), are merely other forms of Smerdis. The former writer calls him Merdis, the latter Merdis or Mergis.

Both Herodotus and Ctesias, however, agree in the most important part of the history, namely that the usurper was a Magian. The true nature of the revolution has been pointed out by Heeren and Grote. It was an attempt on the part of the Medes, to whom the Magians belonged, to obtain the supremacy, of which they had been deprived by Cyrus. This appears from the words which Herodotus (3.65) puts into the mouth of Cambyses on his death-bed, in which he adjures the Persians not to allow the sovereignty to revert again to the Medes, as well as from the speeches of Gobryas, one of the seven Persian conspirators (Hdt. 3.73), and of Prexaspes (3.75). Plato (de Leg. iii. p. 695) in like manner, says that Cambyses was deprived of the sovereignty by the Medes. The assassination of the false Smerdis and the accession of Dareius Hystaspis again gave the ascendancy to the Persians ; and the anniversary of the day on which the Magians were massacred, was commemorated among the Persians by a solemn festival, called Magophonia, on which no Magian was allowed to show himself in public. The real nature of the transaction is also shown by the revolt of the Medes which followed the accession of Dareius. (Heeren, Historical Researches, vol. i. p. 346, Engl. Transl. ; Grote, Hist. of Greece, vol. iv. pp. 296-304.)