“Feridun Strikes Zahak With The Ox-Headed Mace,” watercolor on paper, Tabriz, Iran, circa 1525, from Firdawsi’s “Shahnameh” / Smithsonian Institution
Old Persian Epigraphy: The Bisotun Inscription
Behistun (Bisotun) Inscription, describing conquests of Darius the Great in Old Persian, Elamite, and Babylonian languages. These reliefs and texts are engraved in a cliff on Mount Behistun (present Kermanshah Province, Iran) / Photo by Hara1603, Wikimedia Commons
According to Darius’ inscription at Bisotun (composed in the late sixth century BCE),  King Cambyses killed his brother Bardiya on the eve of his Egyptian campaign without the people (kāra-) being aware of his crime.  During the king’s absence in Egypt, according to the inscription, a magus called Gaumāta usurped the throne by claiming to be prince Bardiya:
Kambūjiya nāma Kurauš puça amāxam taumāyā ha[uv] (par)uvam idā xšāyaθiya āha. Avahạyā Kambūjiyahạyā brāt[ā Bạrdi]ya nāma āha hamātā hamapitā Kambūjiyahạyā. Pasāva Kamb[ūjiya] avam Bạrdiyam avāja yaθā Kambūjiya Bạrdiyam avāja kārahạy[ā naiy] azdā abava taya Bạrdiya avajatā. Pasāva Kambūjiya Mudrāyam [ašiyav]a. Yaθā Kambūjiya Mudrāyam ašiyava pasāva kāra arīka abava [utā] drauga dahạyauvā vasiy abava utā Parsaiy utā Mādaiy u[tā a]niyāuvā dahạyušuvā … Pa[sāva] aiva martiya maguš āha Gaumāta nāma hauv udapatatā hacā Paiši[yā]uvādā Arakadriš nāma kaufa hacā avadaša Viyaxanahạyā mā[h]ạyā XIV raucabiš θakatā āha yadiy udapatatā. Hauv kārahạyā avaθā [a]durujiya adam Bạrdiya amiy haya Kurauš puça Kambūjiyahạyā br[ā]tā.
Cambyses by name, the son of Cyrus, of our family, he was formerly king here. That Cambyses had a brother, Bardiya by name, of the same father and the same mother as Cambyses. Afterwards, Cambyses killed that Bardiya; when Cambyses killed Bardiya, it did not become known to the people that Bardiya was killed. Then Cambyses went to Egypt. When Cambyses went to Egypt, then the people became disloyal and the lie became great, in Persis as well as Media and the other countries … Thereafter, there was one man, a magus, Gaumāta by name, he rose up from Paišiyāuvāda, a mountain by name of Arakadri, from there, of the month of Viyaxna fourteen days were past, when he rose up. He lied to the people thus: “I am Bardiya, son of Cyrus, brother of Cambyses.”
As a result of this claim, the people rose up against Cambyses and went over to Gaumāta, thus enabling him to take possession of the empire:
Pasāva kāra haruva hamiçiya abava hacā Kambūjiyā abiy avam [a]šiyava utā Pārsa utā Māda utā aniyā dahạyāva xšaçam hauv agạrbāyatā Garmapa-dahạyā māhạyā IX raucabiš θakatā āha avaθā xšaçam agạrbāyatā. Pasāva Kambūjiya huvāmạršiyuš amariyatā.
Thereafter, all the people became rebellious, and from Cambyses went over to him, Persis as well as Media and other lands; of the month Garmapada nine days were passed when he seized power. Afterwards, Cambyses died a natural death.
Following Cambyses’ death, nobody dared to contest Gaumāta’s seizure of power, for he would put to death all those who had previously known Bardiya. Darius, helped by a few followers, confronted Gaumāta and finally killed him in Media:
Naiy āha martiya naiy Pārsa naiy Māda naiy amāxam taumāyā kašciy haya avam Gaumātam tayam magum xšaçam dītam caxriyā kārašim hacā dạršam atạrsa kāram vasiy avājaniyā haya paranam Bạrdiyam adānā avahạyarādiy kāram avājaniyā mātayamām xšnāsātiy taya adam naiy Bạrdiya amiy haya Kurauš puça. Kašciy naiy adạršnauš cišciy θanstanaiy pariy Gaumātam tayam magum yātā adam arsam … avaθā adam hadā kamnaibiš martiyabiš avam Gaumātam tayam magum avājanam utā tayaišaiy fratamā martiyā anušiyā āhantā … Mādaiy avadašim avājanam xšaçamšim adam adinam vašnā Ahuramazdāha adam xšāyaθiya abavam Ahuramazdā xšaçam manā frābara.
There was not a (single) man, neither Persian, Mede, nor anybody of our family, who would have taken the power from that magus Gaumāta; the people were much afraid of him, (for) he killed many people, who previously had known Bardiya, for that reason he killed the people, so that “they may not recognize me, that I am not Bardiya, son of Cyrus.” Nobody dared say anything about Gaumāta the magus, until I arrived … then I killed, together with a few men, Gaumāta the magus and those men who were his foremost loyal followers … In Media, there I killed him, the power I took (back) from him, by the favor of Ahuramazda I became king, Ahuramazda gave me the power.
Main Classical Sources
A Roman copy (2nd century AD) of a Greek bust of Herodotus from the first half of the 4th century BC / Wikimedia Commons, Metropolitan Museum of Art, New York
According to the version told by Herodotus  —a native of Halicarnassus and citizen of the Persian empire who wrote his Historiae in the fifth century BCE—two magian brothers, Smerdis and Patizeithēs, usurped the throne during Cam-byses’ absence in Egypt. Patizeithēs, who had been appointed governor of the royal house, concomitantly with Cambyses’ assassination of his brother Smerdis, used the king’s absence from the heartland to rebel:
Καμβύσῃ δὲ τῷ Κύρου χρονίζοντι περὶ Αἴγυπτον καὶ παραφρονήσαντι ἐπανιστέαται ἄνδρες μάγοι δύο ἀδελφεοί, τῶν τὸν ἕτερον καταλελοίπεε τῶν οἰκίων μελεδωνὸν ὁ Καμβύσης. οὗτος δὴ ὦν οἱ ἐπανέστη μαθών τε τὸν Σμέρδιος θάνατον ὡς κρύπτοιτο γενόμενος καὶ ὡς ὀλίγοι εἴησαν οἱ ἐπιστάμενοι αὐτὸν Περσέων οἱ δὲ πολλοὶ περιεόντα μιν εἰδείησαν. πρὸς ταῦτα βουλεύσας τάδε ἐπεχείρησε τοῖσι βασιληίοισι.
Now after Cambyses son of Cyrus had lost his wits, while he still lingered in Egypt, two magi, who were brothers, rebelled against him. One of them had been left by Cambyses to be steward of his house; this man now revolted from him, perceiving that the death of Smerdis had been kept secret, and that few persons knew of it, most of them believing him to be still alive. Therefore, he thus plotted to gain the royal power.
Patizeithēs’ own brother Smerdis resembled the defunct prince Smerdis to such a degree that he could be substituted for the prince without the people recognizing this subterfuge. Therefore, Patizeithēs established his brother on the throne and proclaimed his accession throughout the empire:
ἦν οἱ ἀδελφέος τὸν εἶπά οἱ συνεπαναστῆναι οἰκὼς μάλιστα τὸ εἶδος Σμέρδι τῷ Κύρου, τὸν ὁ Καμβύσης ἐόντα ἑωυτοῦ ἀδελφεόν ἀπέκτεινε· ἦν τε δὴ ὅμοιος εἶδος τῷ Σμέρδι καὶ δὴ καὶ οὔνομα τὠυτὸ εἶχε Σμέρδιν. τοῦτον τὸν ἄνδρα ἀναγνώσας ὁ μάγος Πατιζείθης ὥς οἱ αὐτὸς πάντα διαπρήξει εἷσε ἄγων ἐς τὸν βασιλήιον θρόνον.
He had a brother, his partner, as I said, in rebellion; this brother was very like in appearance to Cyrus’ son, Smerdis, brother of Cambyses and by him put to death; nor was he like him in appearance only, but he bore the same name also, Smerdis. Patizeithēs the magus persuaded this man that he, Patizeithēs, would manage the whole business for him; he brought his brother and set him on the royal throne.
In response to this, Darius and a handful of his companions fomented a coup d’état and killed the two magi in their palace:
οἱ δὲ δὴ ἑπτὰ τῶν Περσέων ὡς ἐβουλεύσαντο αὐτίκα ἐπιχειρέειν τοῖσι µάγοισι καὶ μὴ ὑπερβάλλεσθαι …
The Seven Persians  wished to attack the magi at once, and not to de-lay …
ἀποκτείναντες δὲ τοὺς µάγους καὶ ἀποταμόντες αὐτῶν τὰς κεφαλὰς τοὺς μὲν τρωματίας ἑωυτῶν αὐτοῦ λείπουσι καὶ ἀδυνασίης εἵνεκεν καὶ φυλακῆς τῆς ἀκροπόλιος· οἱ δὲ πέντε αὐτῶν ἔχοντες τῶν µάγων τὰς κεφαλὰς ἔθεον ἔξω βοῇ τε καὶ πατάγῳ χρεώμενοι καὶ Πέρσας τοὺς ἄλλους ἐπεκαλέοντο ἐξηγεομενοί τε τὸ πρῆγμα καὶ δεικνύοντες τὰς κεφαλάς·
Having killed the magi and cut off their heads, they left their wounded where they were, by reason of their infirmity and in order to guard the citadel; the other five took the magi’s heads and ran with shouting and noise, calling all Persians to aid, telling them what they had done and showing the heads.
Justin’s Epitome of Pompeius Trogus
Tomb of Cambyses I, Pasargad, Iran / Photo by Soroush90gh, Wikimedia Commons
Pompeius Trogus—whose work, possibly composed in the Augustan age, is no longer extant and has only survived in the epitome made by Justin sometime at the turn of the second to the third century CE —also denounces two magi as “usurpers.” In this case they are called Cometes and Oropastes. These magi correspond, with respect to their function, exactly to the two described by Hero-dotus. In Pompeius Trogus’ account, however, Cometes himself, the counter-part to Herodotus’ Patizeithēs, was ordered by Cambyses to assassinate the younger prince, called here Mergis. Cambyses’ plan to assassinate his brother was the result of a dream he had while on his Egyptian campaign, which portended that his brother would hold the royal throne:
Post haec per quietem vidit fratrem suum Mergidem regnaturum. Quo somnio exterritus non dubitavit post sacrilegia etiam parricidium facere. Erat enim difficile ut parceret suis qui cum contemptu religionis grassatus etiam adversus deos fuerat. Ad hoc tam crudele ministerium magum quendam ex amicis delegit nomine Cometen. Interim ipse gladio sua sponte evaginato in femur graviter vulneratus occubuit poenasque luit seu imperati parricidii seu perpetrati sacrilegii.
Thereupon, he saw in a dream that his brother Mergis was going to rule. Terrified by the dream, he did not hesitate also to commit fratricide, following [past] sacrilege [in Egypt]. It was indeed difficult that one who had opposed even the gods, because of [his] contempt of religion, would spare his kin. In order to fulfill such cruel task, he chose a magus of his acquaintance, by the name of Cometes. Meanwhile, he [Cambyses] himself died, wounding [his] groin by his own sword, which had come out of its sheath, and received the punishment of either the fratricide he had ordered or the sacrilege he had perpetrated.
Notwithstanding the king’s death before the fulfillment of his order, and the succession devolving upon Prince Mergis, cui regnum debebatur, Cambyses’ magian accomplice Cometes killed Mergis, in order to raise to the throne his own brother Oropastes, who resembled the prince in all respects. The subterfuge remained undetected, for apud Persas persona regis sub specie maiestatis occulitur:
Quo nuntio accepto magus ante famam amissi regis occupat facinus prostratoque Mergide cui regnum debebatur fratrem suum subiecit Oropasten. Erat enim et oris et corporis liniamentis persimilis ac nemine subesse dolum arbitrante pro Mergide rex Oropasta constitu-itur. Quae res eo occultior fuit quod apud Persas persona regis sub specie maiestatis occulitur. Igitur magi ad favorem populi conciliandum tributa et militiae vacationem in triennium remittunt ut regnum quod fraude quaesierant indulgentiae largitionibus confirmarent.
Having received the news of the king’s demise, the magus, before the rumor would set in, accomplished his evil deed, and once Mergis, to whom the throne would have passed on, was killed, he substituted his own bother Oropastes for him. Indeed, he was, as the features of his face and body are concerned, very similar [to Mergis], and without anybody imagining a deceit, King Oropasta was established in Mergis’ stead. And the matter (about him) was the more veiled, as among the Persians, the king’s person is concealed, under the pretext of his majesty. Then the magi in order to gain the favor of the populace remitted for three years tribute and granted dispensation from military service and (thereby) bolstered the kingship, which they had gained by fraud, through indulgent largess.
However, the substitution was discovered by Otanes, a Persian nobleman, who with the help of his daughter, a concubine in Oropastes’ harem, was able to determine the true identity of the magus:
Quae res suspecta primo Hostani viro nobili et in coniectura sagacissimo fuit. Itaque per internuntios quaerit de filia quae inter regias pae-lices erat an Cyri filius rex esset. Illa nec se ipsam scire ait nec ex alia posse cognoscere quia singulae separatim recludantur. Tum pertractare caput dormienti iubet nam mago Cambyses aures utrasque praeciderat. Factus dein per filiam certior sine auribus regem esse optimatibus Persarum rem indicat et in caedem falsi regis inpulsos sacramenti religione obstringit.
The matter appeared first to be suspect to Hostanes, a nobleman, who, when called for, was most wise. Thus, through the intermediary of go-betweens he inquires of his daughter, who was among the royal concubines, whether the king was Cyrus’ son. This one said she neither knew it by herself, nor could have knowledge of it through others, for they are all enclosed separately. Thus, he orders her to feel the king’s head, while asleep, for Cambyses had cut the magus’ ears. Thereupon, assured by his daughter that the king had no ears, he denounces the matter to the noblest among the Persians, and binds by oath those he has urged on to strike the false king.
Once Hostanes discovered the identity of the false king, he fomented a plot to eliminate the latter by involving only seven conspirators:
Septem tantum conscii fuere huius coniurationis qui ex continenti ne dato in paenitentiam spatio res per quemcumque narraretur occultato sub veste ferro ad regiam pergunt. Ibi obviis interfectis ad magos perveniunt quibus ne ipsis quidem animus in auxilium sui defuit siquidem stricto ferro duos de coniuratis interficiunt. Ipsi tamen corripiuntur a pluribus quorum alterum Gobryas medium amplexus cunctantibus sociis ne ipsum pro mago transfoderent quia res obscuro loco gerebatur vel per suum corpus adigi mago ferrum iussit. Fortuna tamen ita regente illo incolumi magus interficitur.
They were only seven to be aware of this conspiracy, who without delay, and so that whoever having had leisure to repent may not speak of the matter, proceeded to the court, with a sword hidden in their robes. Having destroyed there all who were on their way, they reached the magi, whom the spirit of providing help to each other certainly did not fail, for with their drawn sword they killed two of the conspirators. Yet, they themselves are seized by the many, among the latter Gobryas, who, holding the middle (waist) [of one of the magi], while his comrades hesitated, so they may not pierce him instead of the magus, for the event was unfolding at a dark location, commanded to strike with the blade the magus, even through his own body. But fortune having thus decided, the magus was killed, while he [Gobryas] was unharmed.
Daric of Artaxerxes II / Photo by Marie-Lan Nguyen, Wikimedia Commons, Cabinet des Médailles
In analogy to the Bisotun inscription’s testimony, Cteseas—the personal physician of King Artaxerxes Mnemon and his family, who most likely lived during the second half of fifth and first decades of the fourth century BCE—recognizes only a single “usurper,” a magus by the name of Sphendadatēs.  According to Ctesias, this magus, having been punished before by the royal prince Bardiya (here called Tanyoxarkēs), falsely accused Tanyoxarkēs to Cambyses of fomenting a rebellion, implicitly in order to exact vengeance upon the prince:
Μάγος δέ τις Σφενδαδάτης ὄνομα ἁμαρτήσας καὶ μαστιγωθεὶς ὑπὸ Τανυοξάρκου ἀφικνεῖται πρὸς Καμβύσην ἐνδιαβάλλων τὸν ἀδελφὸν Τανυοξάρκην ὡς ἐπιβουλεύντα αὐτῷ.
A magus called Sphendadatēs, who had committed a wrong and had been whipped by Tanyoxarkēs [=Bardiya], came to Cambyses and accused his brother Tanyoxarkēs to conspire against him.
Ctesias further reports that the magus Sphendadatēs devised a plan to have himself subjected to a public execution for having falsely accused the prince, while in reality it was Prince Tanyoxarkēs who would be beheaded instead of Sphendadatēs. The result was to be that Sphendadatēs, who physically resembled the executed Tanyoxarkēs, could assume his position in life, taking on the governorship of Bactria:
ὁ γάρ τοι μάγος βουλῆς τῷ βασιλεῖ κοινωνῶν βουλεύει τοιοῦτον· ὅμοιος ἦν αὐτὸς ὁ μάγος κάρτα τῷ Τανυοξάρκῃ· βουλεύει τοιγαροῦν αὐτὸν μὲν ἐν τῷ φανερῷ ὡς δῆθεν ἀδελφοῦ βασιλέως κατειπόντα τὴν κεφαλὴν προστάξαι ἀποτμηθῆναι ἐν δὲ τῷ κρυπτῷ ἀναιρεθῆναι Τανυοξάρκην καὶ τὴν ἐκείνου στολὴν ἀμφιασθῆναι τὸν μάγον ὥστε καὶ τῷ ἀμφιάσματι νομίζεσθαι Τανυοξάρκην.
The magus in concert with the king devised the following plan. This magus resembled Tanyoxarkēs very much. For that very reason, he proposes that an order be given publicly to cut off his (the magus’) head, for having denounced the king’s brother, but (in reality) Tanyoxarkēs be killed in secret, and the magusbe clad in that person’s robe, so that he would be considered to be Tanyoxarkēs on account of the garment.
Nobody was informed of this substitution, except the closest members of Cambyses’ entourage: Arasyras, Bagapetes, and Izabates. Five years after the substitution, the queen mother Amytis discovered the truth and demanded the head of the magus; upon being refused by Cambyses, she took poison and damned her older son before dying. 
Ctesias further recounts that before the death of Cambyses, even prior to the Egyptian campaign, two of Cambyses’ grandees—Bagapatēs and Artasyras—had decided to make Sphendadatēs king, which they then accomplished upon Cambyses’ death:
Βαγαπάτης δὲ καὶ Ἀρτασύρας πρὶν ᾒ Καμβύσης τελευτήσει ἐβουλεύσαντο βασιλεῦσαι τὸν μάγον· καὶ ἐβασίλευσεν ἐκείνου τελευτήσαντος.
Bagapatēs and Artasyras had decided before Cambyses died that the magus would be king and, in fact, he ruled after his death.
Thus, although there is only a single magus in Ctesias’ account, the role played by the duo Bagapatēs and Artasyras recalls the one assumed in the Herodotean plot by Patizeithēs and in Trogus by Cometes. Bagapatēs is labeled a eunuch,  and in spite of the difficulty in defining to whom in Ctesias’ narrative and in the later Greek tradition generally the term “eunuch” was attributed,  it may well have served as a designation for members of the priesthood, the magi. A passage of Plato, wherein the “usurper,” known elsewhere as the magus, is called “eunuch,” supports this:
παραλαβόντες δ᾿ οὖν οἱ παῖδες τελευτήσαντος Κύρου τρυφῆς μεστοὶ καὶ ἀνεπιπληξίας πρῶτον μὲν τὸν ἕτερον ἅτερος ἀπέκτεινε τῷ ἴσῳ ἀγανακτῶν μετὰ δὲ τοῦτο αὐτὸς μαινόμενος ὑπὸ μέθης τε καὶ ἀπαι-δευσίας τὴν ἀρχὴν ἀπώλεσεν ὑπὸ Μήδων τε καὶ τοῦ λεγομένου τότε εὐνούχου καταφρονήσαντος τῆς Καμβύσου μωρίας.
So then at the death of Cyrus, his sons succeeded him, full of wantonness and licentiousness; first, one slew the other, vexed at his equal, and thereupon, driven mad by strong drink and self-indulgence, he lost the throne by the hands of the Medes, and the one then called the Eunuch, who despised the folly of Cambyses.
Plato, Laws 3.695b
What is striking in this passage is that the story of the two magian usurpers—whose functions, within the accounts of Herodotus and Trogus, are divided between those of kingmaker (Patizeithēs/Cometes) and puppet-king (Smerdis/Oropastes)—has been altered through the influence of the Bisotun narrative to such an extent that the puppet-king now has no brother conspirator; instead, the original function of the kingmaker is fulfilled by a duo of plotters, one of whom is a eunuch (magus?). In a sense, while the binary functions known from the story of the pair of magian usurpers are maintained in Ctesias, each of these (functions) is associated with the respective actor(s) of competing narratives: puppet-king with the single magus of Bisotun, and the kingmaker with the two usurpers captured by Herodotus and Trogus, as illustrated here:
Dionysius of Miletus, Hellanicus of Lesbos, and Aeschylus
Bust of Aeschylus, Zappeion, Athens, by Tilemachos Efthimiadis / Wikimedia Commons
The testimony of Dionysius of Miletus, a contemporary of Darius I and Hecataeus of Miletus,  on the events following Cambyses’ demise is preserved only in a late scholion commenting on Herodotus’ account of the selfsame events; it reads as follows:
τοῦτον τὸν ἄνδρα ἀναγνώσας ὁ μάγος Πατιζείθης ὥς οἱ αὐτὸς πάντα διαπρήξει εἷσε ἄγων ἐς τὸν βασιλήιον θρόνον. Διονύσιος ὁ Μιλήσιος Πανξούθην ὀνομάζεσθαι τοῦτον λέγει.
Patizeithēs the magus persuaded this man that he, Patizeithēs, would manage the whole business for him; he brought his brother and set him on the royal throne. Dionysius the Milesian says that he was called Panxouthēs.
FGH IIIC, 687, F2, 411
Another scholion—this one attributed to Hellanicus of Lesbos,  in a com-ment on Aeschylus’ Persians—is also worthy of attention, as it seems to refer to two usurpers as well:
Κύρου ὑιὸς Καμβύσης· ἀδελφοὶ δὲ κατὰ Ἑλλάνικον Μάραφις Μέρφις.
Cyrus’ son Cambyses had, according to Hellanicus, two brothers: Maraphis and Merphis. 
FGH IIIC, 687a, F8, 414
Since Cambyses had merely one brother—on which point all of our sources, despite otherwise considerable variations, seem to agree—the question re-mains as to the reason for the duplication of the singleton in this scholion. Un-doubtedly, the story of the two magian brethren in the accounts of Herodotus and Trogus ought to have colored the scholion attributed to Hellanicus. It is very likely that Hellanicus himself had retained only the story of two brothers, Merphis and Maraphis, with the former being fashioned in analogy with the name of the usurper as it appears in Aeschylus, as Μάρδος, or in Herodotus, as Σμέρδις. The identification by the later scholiasts of one of the magian brothers with Bardiya, on account of his perfect resemblance with the latter, probably led to the two magians jointly becoming brethren to Cambyses. Thus, we ought to assume that, aside from Herodotus and Trogus’ source, Hellanicus also knew of two usurper brothers, although no word of their being magi is mentioned.
Intriguingly, in a passage of Aeschylus’ Persians, the spirit (δαίμων) of Darius—summoned by Queen Atossa, Darius’ widow, and Persian dignitaries, the defunct king’s old companions,  who are decrying the defeat of Xerxes’ armies in Hellas—enumerates a list of Persian rulers who had governed before him. In this list, the Herodotean Smerdis is called Mardos, who, although depicted negatively, is still not explicitly identified as an impostor.  Surprisingly, a certain Maraphis, who supposedly came after Mardos, also appears. The passage in question reads as follows:
Κύρου δὲ παῖς τέταρτος ηὔθυνε στρατόν·
πέμπτος δὲ Μάρδος ἦρξεν αἰσχύνη πάτραι
θρόνοισί τ᾿ ἀρχαίοισι· τὸν δὲ σὺν δόλωι
Ἀρταφρένης ἔκτεινεν ἐσθλὸς ἐν δόμοις
ξὺν ἀνδράσιν φίλοισιν οἷς τόδ᾿ ἦν χρέος.
ἓκτος δὲ Μάραφις· ἕβδομος δ᾿ Ἀρταφρένης
κἀγὼ· πάλου τ᾿ ἔκυρσα τοῦπερ ἤθελον
κἀπεστράτευσα πολλὰ σὺν πολλῶι στρατῶι. 
The son of Cyrus led as fourth the army.
Mardos governed as fifth, a shame to his native land
and to the ancient throne; but through a cunning plot
the brave/fortunate Artaphrenēs slew him in his chambers,
together with friends, whose duty this was.
Sixth (was) Maraphis; and seventh (it was between) Artaphrenēs
and me ; I obtained the lot I desired,
and made many wars with a mighty force.
Aeschylus, Persians 773–780
Aeschylus’ Maraphis, whose authenticity within this text has been traditionally questioned,  corresponded to Hellanicus’ homonymous personage Maraphis. Indeed, in this passage Mar-dos and Maraphis, who are listed as independent rulers before the rise of Darius, may represent a rationalizing reworking by Aeschylus of the story of two usurper-brothers, who were captured with some variation as Merphis and Mara-phis by Hellanicus, but who are here made into two subsequent rulers, rather than fellow conspirators.
This possibility, as well as the problematic issue of the presence within Aeschylus’ list of Artaphrenēs, one of Darius’ fellow conspirators in killing the magi, will be discussed below.
Minor, Late Antique, and Syriac Sources
The Greek historian Xenophon of Athens / Wikimedia Commons, Marmorbüste im Kgl. Museum, Berlin
Xenophon, in his Cyropaedia, touches on the events following Cyrus’ death.  He begins his account with Cyrus’ attempting to determine the succession of his children to the Achaemenid throne, by summoning, on the eve of his demise, his friends, his children, and various Persian nobles:
ἐκάλεσε τοὺς παῖδας· οἱ δ᾿ ἔτυχον συνηκολουθηκότες αὐτῷ καὶ ὄντες ἐν Πέρσαις· ἐκάλεσε δὲ καὶ τοὺς φίλους καὶ τὰς Περσῶν ἀρχάς.
He [Cyrus] summoned his children; for they had accompanied him and were still in Persis. He also summoned his friends, as well as the grandees among the Persians.
Xenophon, Cyropaedia 8.7.5
According to Xenophon, the throne was given to Cambyses—καὶ σὺ μὲν ὦ Καμβύση τὴν βασιλείαν ἔχε  “and you, O Cambyses, shall hold the throne”—whereas Tanaoxarēs, Cambyses’ brother, the Ctesian Tanyoxarkēs, was designated as satrap over numerous lands—σοὶ δ᾿ ὦ Ταναοξάρη σατράπην εἶναι δίδωμι Μήδων τε καὶ Ἀρνμενίων καὶ τρίτων Καδουσίων  “to you, O Tanaoxarēs, I grant (the right) of being satrap over the Medes, Armenians, and in the third place, the Cadusians.”
Of interest in Xenophon’s account is the indication that dissent among Cyrus’ children (and within the empire) erupted following his death: ἐπεὶ μέντοι Κῦρος ἐτελεύτησεν εὐθὺς μὲν αὐτοῦ οἱ παῖδες ἐστασίαζον εὐθὺς δὲ πόλεις καὶ ἔθνη ἀφίσταντο πάντα δ᾿ ἐπὶ τὸ χεῖρον ἐτρέπετο,  “to be sure, once Cyrus had come to his end, his children at once quarreled with each other, and cities and peoples openly revolted.” Intriguingly, no allusions to a magian conspiracy, or “usurpation,” are made, and the conflict is perceived to have been limited to the dissension between the brothers. While Xenophon follows other sources, such as Herodotus and Ctesias, in reporting a conflict between the brothers, the desertion of cities and peoples, which he seems to attribute to their quarrel, may be but a reflex of the great rebellions throughout the empire that ensued after the accession of Darius I.
Strabo as depicted in a 16th-century engraving / Scanned by Brian Boru, Wikimedia Commons, from Strabo’s Geographica, chapter 35
Strabo  provides a brief note on the magian “usurpation” that adds nothing substantial to what is already well known from other sources:
διαδεξάμενος δὲ τοῦτον Καμβύσης υἱὸς ὑπὸ τῶν μάγων κατελύθη· τού-τους δ᾿ ἀνελόντες οἱ ἑπτὰ Πέρσαι Δαρείῳ τῷ Ὑστάσπεως παρέδοσαν τὴν ἀρχήν.
To him [Cyrus], his son, Cambyses, who was deposed by the magi, succeeded. The Seven Persians who bestowed the empire upon Darius, son of Hystaspes, killed them [the magi].
Bust of Plutarch at Chaeronea / Photo by Odysses, Wikimedia Commons
Equally scant is Plutarch’s account, in the Moralia, of the “magus’ usurpation.”  Following Herodotus and Ctesias, Plutarch reports that Cambyses’ intention to murder his brother was consequent upon a dream revealing the future rule of the latter. Thus, with Cambyses having committed fratricide and then in turn dying, Cyrus’ line vanished and the empire passed into Darius’ hands:
ὅθεν ἐξέπεσε τῆς Κύρου διαδοχῆς ἡ ἀρχὴ τελευτήσαντος αὐτοῦ καὶ τὸ Δαρείου γένος ἐβασίλευσεν ἀνδρὸς οὐ μόνον ἀδελφοῖς ἀλλὰ καὶ φίλοις ἐπισταμένου κοινωνεῖν πραγμάτων καὶ δυνάμεως.
This is why, following his [Cambyses’] death, the empire was taken from Cyrus’ successors, and Darius’ family—the family of a man who knew how to share power and govern in community not only with his brethren, but also with his friends—ruled.
Plutarch, Moralia 490A
At first glance, Plutarch’s report does not substantially diverge from the testimonies of our main sources, although it is worth noting that in his account Cambyses’ brother would have inherited the throne, had the king not previously assassinated him. Thus, at least in Plutarch’s narrative, Bardiya is implicit-ly deemed to have been a virtual successor.
In yet another passage of the Moralia, Plutarch depicts paucis verba the killing of the magus by Darius. Of the Seven Persians, only two, namely, Darius and Gobryas, are mentioned. The latter having engaged the magus in single combat, exhorted Darius—who had been hesitant to help his companion out of fear of harming him—to strike their opponent with the sword. 
The romanticized engraving of Flavius Josephus appearing in William Whiston’s translation of his works, 1817 / Wikimedia Commons
In his first-century CE Jewish Antiquities, Josephus briefly mentions Darius’ accession, which followed upon the death of Cambyses in Damascus after he returned from the Egyptian campaign. The magi, having seized power in Persia, fell prey shortly thereafter to the coup d’état of the Seven:
μετὰ δὲ τὴν τῶν μάγων ἀναίρεσιν οἳ μετὰ τὸν Καμβύσου θάνατον τὴν Περσῶν ἀρχὴν ἐνιαυτῷ κατέσχον οἱ λεγόμενοι ἑπτὰ οἶκοι τῶν Περσῶν τὸν Ὑστάπου παῖδα Δαρεῖον ἀπέδειξαν βασιλέα.
Following the assassination of the magi, who held power in Persia in the year following the death of Cambyses, the so-called seven families of the Persians chose Darius, son of Hystaspes, as king.
Josephus, Jewish Antiquities 11.31
The walls of Amida, built by Constantius II before the Siege of Amida of 359. Ammianus himself was present in the city until a day before its fall. / Photo by Gerry Lynch (2003), Wikimedia Commons
Among the more reliable sources of late antiquity is Ammianus Marcellinus, who is viewed as a dependable eyewitness and commentator on Roman and Sasanian interactions in the second half of the fourth century CE. 
He reports the following on the events of 522–521:
Ex hoc magorum semine Septem post mortem Cambysis regnum inisse Persidos antiqui memorant libri docentes eos Darei factione oppressos imperitandi initium equino hinnitu sortiti.
Seven from among this tribe of magi held after Cambyses’ death the kingship, as old scriptures reveal it (to us). They report that they were crushed by Darius’ faction.
Ammianus Marcellinus 23.6.36
Noteworthy in this testimony is the metamorphosis of Darius’ helpers, the Seven (conspirators), into seven magi, whom Darius would eventually eliminate.
Paulus Orosius, shown in a miniature from the Saint-Epure codex (Códice de Saint-Epure) / Wikimedia Commons
Orosius’ account  of the Gaumāta affair relies heavily on the narrative of Pom-peius Trogus/Justin.  As he relates:
Regnavit enim medius eorum Cambyses Cyri filius qui devicta Aegypto cunctam Aegypti religionem abominatus caerimonias eius et templa deposuit. Post hunc etiam magi sub nomine quem occiderant regis regno obrepere ausi qui quidem mox deprehensi et oppressi sunt. Darius itaque unus ex his qui magorum audaciam ferro coercuerant consensu omnium rex creatus est.
Indeed, between them ruled Cambyses, son of Cyrus, who after having defeated Egypt, abhorred the whole religion of Egypt, and abolished its rituals and temples. Thereafter, the magi attempted to take possession of the kingship in the name (under the guise of) of the king, whom they had slain. They were, however, discovered and later eliminated. Thus, Darius, one among those who punished the audacity of the magi by the sword, became, through general consent, king.
The Syriac Apocalypse of Daniel
In the recently re-edited and annotated Syriac Apocalypse of Daniel, which in all probability was written in the second half of the seventh century CE,  we find a rarely noted allusion to the Gaumāta “usurpation” that is heavily interwoven with the legend of King Solomon’s throne.  What is intriguing in this short passage, fully reproduced below, is the correct use of Gaumāta’s name, written gmt mgwšʾ “(the) magus Gemath”; aside from the Bisotun inscription, the name is only correctly reflected in Justin’s epitome of Trogus, as “Cometes.”
As they were going up from Babylon to Persia and Elam, King Cyrus put these implements away with great reverence. And it was shown to him by God that he should go and deposit them in the mountain of Elam, in the mountain called Zilai after the name of Mount Sinai, in order that they would keep [them there] until the latter time. He also inscribed a stone with a clean side and placed it together with the implements [in the mountain]. Only the golden throne on which King Solomon used to sit did the king spare and kept it in the treasury. In the middle of the night Gemath the magus [gmt mgwšʾ] rose, killed Cyrus, and seized the kingship in Persia. I became afraid and fled among the cities of Persia and Elam lest he kill me—for I had been a courtier of King Cyrus—and lest I should have to go and show him that mountain in which those implements were deposited which King Cyrus had brought from Babylon. For he [Gemath] had entered the treasury of King Cyrus and had found King Solomon’s golden throne. Gemath brought it out, sat on it, and became boastful and blasphemous. It was shown to me by God that the kingdom was to remain for a short while only. The kingdom of Gemath the magus [who ruled] after Cyrus the Persian lasted six months, and his nobles plotted against him and killed him, and seized the kingship of Darius bar Bagdath bar Artaban [drywš br bgdt br ʾrṭbn] and assumed that authority of Cyrus, king of Persia, and stood in the Gate of Kings.
Syriac Apocalypse of Daniel 8–9
Much of the information pertaining to the Gaumāta episode here seems to be drawn, at least partially, from the text of Darius’ res gestae, the Bisotun inscription itself, most likely its Aramaic translation. Numerous revealing parallels between the Syriac Apocalypse of Daniel and the Bisotun inscription are tabulated on the next page.
Syriac Apocalypse of Daniel 9:
Gemath the magus rose, killed Cyrus, and seized the kingship in Persia.
Gemath brought it [the throne] out, sat on it, and became boastful and blasphemous.
Garmapadahạyā māḥyā IX raucabiš θakatā āha avaθā xšaçam agạrbāyatā (“Of the month of Garmapada nine days were passed when he seized power”).
xšaçam taya haca amāxam taumāyā parābạrtam āhaava adam patipadamakunavam adamšim gāθavā avāstāyam (“The royalty which was taken away from our family I put in (its) place, I established it in place”).
Syriac Apocalypse of Daniel 9:
“I became afraid and fled among the cities of Persia and Elam lest hekill me—for I had been a courtier of King Cyrus.”
kārašim hacā dạršam atạrsa kāram vasiy avājaniyā haya paranam Bạrdiyam adānā avahạyarādiy kāram avājaniyā mātayamām xšnāsātiy (“The people were much afraid of him, (for) he killed many people, who previously had known Bardiya, for that reason he killed the people, so that: ‘they may not recognize me’ ”).
Syriac Apocalypse of Daniel 9:
His nobles plotted against him and killed him, and seized the kingship of Darius bar Bagdath bar Artaban, and assumed that authority of Cyrus, king of Persia.
avaθā adam hadā kamnaibiš martiyaibiš avam Gaumātam tayam magum avājanam utā tayaišaiy fratamā martiyā anušiyā āha n tā (“Then I together with a few men killed that Gaumāta the magusand the men who were his foremost followers”).
The Syriac Apocalypse of Daniel—which, as mentioned above, was probably composed in the first half of the seventh century CE, from older material that indicates the author’s familiarity with Jewish apocalyptic literature of the first centuries CE —is the only document that evidences the (in)direct use of the Aramaic version of the Bisotun inscription, excluding the Bactrian Rabatak in-scription of Kaniška.
Comparison of Sources
Our major classical sources, namely, Herodotus and Pompeius Trogus/Justin, respectively ascribe to two magi the usurpation of Cambyses’ throne. In Herodotus, they are called Patizeithēs and Smerdis, whereas Justin calls them Cometes and Oropastes. The story pattern and the functions of the magian brothers are almost identical in the two accounts: within each magian couple, there is one crown-bestower/kingmaker, Patizeithēs in Herodotus, Cometes in Justin; and one puppet-king, Smerdis and Oropastes, respectively, who, because of their physical resemblance to Bardiya, could be substituted, through the subterfuge of Patizeithēs or his Justinian counterpart Cometes, for the defunct prince without the knowledge of the people, and, hence, usurp the Achaemenid throne.
Since the name Cometes reflects that of Gaumāta, it is probable that Pompeius Trogus had sources other than Herodotus or Ctesias at his disposal, for these two historians were unaware of the name of Gaumāta. On the other hand, the accounts of both Herodotus and Pompeius Trogus’ Gewährsmann seem to have been subjected to the influence of the Bisotun narrative, as demonstrated by the retention of the correct name of the magus Cometes, and Herodotus’ accurate reference to the names of Darius’ fellow conspirators, which presupposes the partial use of a Greek translation of the Bisotun inscription.
However, the scholion attributed to Hellanicus very likely captures correctly a story wherein two (magian) brothers were involved in the seizure of power in the aftermath of Cambyses’ death. At a later date, however, the scholiasts may have made the two magian brothers into two brothers of Cambyses, in this way following a story pattern of which the accounts of Herodotus and Trogus are variants. Hence, positing that the original account of Hellanicus may have entailed two (magian) brethren, the scholiasts might have identified Cambyses’ brother Bardiya with the magus Merphis—who not only resembled the imperial prince, but with whom he might even have shared the same name—with the result that the latter’s brother Maraphis also became a brother of Cambyses. Thus, the two brothers of Cambyses may have owed their existence to a subsequent alteration of an original pair of magian brethren.
magus, or expressly as a usurper,  nor is there any explicit relationship between him and the next ruler, Maraphis,  of which Aeschylus knows to report. Maraphis would have otherwise remained unknown to us were it not for the scholion ascribed to Hellanicus. As it stands, we may circumspectly assume that the two subsequent rulers, Mardos and Maraphis, of Aeschylus’ list are in reality the rationalizing interpretation within the author’s narrative of two (magian) usurper brothers, whom Aeschylus erroneously interpreted as two independent rulers, with Maraphis following upon Mardos.  This may be schematically illustrated as follows
It remains intriguing, however, that Artaphrenēs, although given the primary role in Aeschylus’ depiction of the magus’ killing, appears as successor only to Maraphis, and not to Mardos, whom he eliminated. Clearly, another (oral) tradition interfered with that of the two brothers, which Hellanicus and, in an altered form, Aeschylus have captured. In Ctesias’ account, the two nobles, Bagapatēs and Artasyras, who made the magus king are also responsible for his downfall; they indeed plot with other nobles to eliminate their former protégé. In that sense they may also reflect the duo that in Herodotus and Justin is most responsible for the killing of the magi, that is, Darius himself and Gobryas. The other conspirators expressly mentioned by name in the mêlée following the storming of the palace are Aspathinēs and Intaphernēs, who, however—being respectively wounded in the thigh and blinded in the eye by one of the magi, and left behind by the remaining five—did not play an active role in the ensuing magophonia. 
Thus, Aeschylus’ Artaphrenes may either represent one of Darius’ most visible helpers, Gobyras, turned into an independent ruler,  or embody the Hero-dotean Intaphernēs,  who, following Darius’ rise to power, was reportedly executed on the latter’s behest, on the face of it, on account of his violating the nascent court protocol, but in reality because of his challenging the king’s authority,  which may account for his inclusion in Aeschylus’ list of Persian potentates.
Should our interpretation of Hellanicus and Aeschylus prove valid, we could say that we have a duplication of the Bisotun inscription’s “usurper” in the majority of our classical sources, except for Ctesias. Before we proceed, in the next chapter, to explore the origins of this duplication of persons and functions, which resulted in the presence of a kingmaker represented by Patizeithēs/Cometes and a puppet-king—or substitute for Bardiya—embodied by Smerdis/Oropastes, we should consider first the account of Ctesias.
Although in Ctesias’ account, Bardiya/Tanyoxarkēs is assassinated by Cambyses himself, the magus Sphendadatēs is ultimately presented as the instigator of the crime, for he is reported to have falsely denounced Tanyoxarkēs to the king, and to have thereby prompted his fall from grace. Following Tanyoxarkēs’ demise, the magus’ astuteness prevents the prince’s assassination from becoming known. It is surely Sphendadatēs’ resemblance to the defunct prince that enables the magus to substitute himself for Tanyoxarkēs and seize the reins of power; but the magus is helped in this task by two additional political figures, Bagapatēs and Artasyras, whom we just encountered as the embodiment of aristocratic plotting against the magus. However, we shall not forget that these two have been equally responsible for the magus’ elevation, and although there is no second magus in Ctesias’ account, the role played by Bagapatēs and Artasyras is certainly comparable to that of Cometes and Oropastes.
Originally published by The Center for Hellenic Studies under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported license. From “Aspects of History and Epic in Ancient Iran: From Gaumāta to Wahnām”, by M. Rahim Shayegan (CHS, 2012).