standing left, holding
aegis over his outstretched left arm and hurling thunderbolt with his right hand, eagle in the field, ΒΑΣΙΛΕΩΣ ΑΝΤΙΟΧΟΥ ('of King Antiochus'). From Shahr-i-Nau,
Hisor District,
Tajikistan.
National Museum of Antiquities of Tajikistan. At some point, Diodotus seceded from the Seleucid empire, establishing his realm as an independent kingdom, known in modern scholarship as the Graeco-Bactrian kingdom. The event is mentioned briefly by the Roman historian
Justin: The date of this event is unclear. The literary evidence is as follows: • Justin says that the rebellion occurred 'around the same time' as the
Parni conquest of Parthia from the Seleucid realm, but his dating of this event is confused—he places it in 256 BC, but during the reign of
Seleucus II (246-225 BC). • Strabo further claims that
Arsaces, the leader of the Parni, had been based in Bactria before the conquest. He says that Diodotus drove Arsaces out of Bactria and maintained hostilities against the Parni. •
Ammianus Marcellinus places the Parthian rebellion in the reign of a Seleucus (II?). •
Arrian's lost
Parthian History seems to have claimed that the Seleucid satrap who was overthrown by the Parthians was appointed to that position by Antiochus II. •
Appian states that the Parthian rebellion took place in 246 BC, during the
Third Syrian War, in the wake of
Ptolemy III's conquest of Seleucid Syria and Babylon. The
Adulis inscription set up by Ptolemy III to celebrate this event claims that Bactria was among Ptolemy's conquests, which is hyperbole but might indicate that Bactria had been part of the Seleucid empire up to this point. Different scholars have argued for a 'High Chronology' which places Diodotus' independence around 255 BC in the reign of Antiochus II, or a 'Low Chronology' which dates the secession around 245 BC at the beginning of the reign of Seleucus II. Several scholars have expressed pessimism about the possibility of resolving this debate with the available evidence. Frank Holt argues that the secession should be seen as a gradual process in which Diodotus and other eastern Seleucid satraps aggregated ever more autonomy, rather than a single event. In his opinion, the process probably began in the 250s BC and was completed in the reign of Seleucus II. By contrast, Jens Jakobssen argues that Diodotus assumed independence suddenly in 246 or 245 BC, in the confusion of the
Third Syrian War, during which it briefly appeared that
Ptolemy III had conquered the Seleucid core territories of
Syria and
Mesopotamia. The limited archaeological evidence reveals no signs of discontinuity or destruction in this period. The transition from Seleucid rule to independence thus seems to have been accomplished peacefully. Archaeologists have identified a number of other settlements which might be other satrapal capitals, including
Yemshi Tepe in
Sar-e Pol,
Dalverzin Tepe in the
Surxondaryo river valley, and
Kobadian in the
Kofarnihon river valley. It is unclear whether Diodotus based himself and his main mint at Ai-Khanoum or
Bactra. The literary sources stress the prosperity of the new kingdom. Justin calls it "the extremely prosperous empire of the thousand cities of Bactria.", while the geographer
Strabo says: Diodotus continued to be hostile to the Parthians for the rest of his reign. Justin emphasises Arsaces' precarious position, opposed by the Seleucids to his west and Diodotus to the east—he is unclear about whether this opposition was co-ordinated. The new king concluded a peace with the Parthians and supported Arsaces when Seleucus II attacked him around 228 BC. ==Coinage==