Diodotus’ career was recounted by Apollodorus of Artemita in the Parthian History, but this text is lost, and surviving literary sources only mention him in passing.

This arrangement would follow the model laid down by the Seleucids, who had made a practice of appointing the crown prince as co-regent and entrusting them with government of the eastern portion of the empire (including Bactria).

It is unclear whether Diodotus was actively involved in the battle or simply agreed to remain neutral, thereby leaving Arsaces free to bring all his forces to bear on the invading Seleucid army.

[8] Archaeological evidence reveals that the city of Ai-Khanoum was besieged around 225 BC, an event which Holt connects with Euthydemus' seizure of power.

The precious metal coinage consisted of gold staters and silver tetradrachms, drachms, and hemidrachms on the Attic weight standard.

[11] This shift in legends seems to reflect the final renunciation of Seleucid authority and a full proclamation of Bactrian independence.

This was accompanied by the production of an issue at the secondary mint, depicting the older figure of Diodotus I once more, but in a more idealised fashion ('series B').

Initially, this coinage bore the same obverse design as that of Diodotus I: head of Hermes wearing a petasus hat ('Series H').

However, the reverse design is new: a depiction of Athena resting on her spear and the introduction of a new legend, reading Ancient Greek: ΒΑΣΙΛΕΩΣ ΔΙΟΔΟΤΟΥ ("of King Diodotus"), as on the gold and silver coinage.

These bronze coins were found in very large numbers in the excavations of Ai-Khanoum and in smaller quantities at Gyaur Gala (Merv, Turkmenistan) and Takht-i Sangin.

The profusion of bronze coinage, whose value was token, especially in the very smallest denominations, indicates the progressive monetisation taking place in Bactria by the time of Diodotus II.