Diodotus II was a Greco-Bactrian king from c. 239 BC, son of Diodotus I

Diodotus I

Diodotus I Soter was Seleucid satrap of Bactria, rebelled against Seleucid rule soon after the death of Antiochus II in c. 255 or 246 BC, and wrested independence for his territory. He died in 239 BC....

. He is known for concluding a peace treaty with the Parthia

Parthia

Parthia is a region of north-eastern Iran, best known for having been the political and cultural base of the Arsacid dynasty, rulers of the Parthian Empire....

n king Arsaces

Arsaces

Arsaces is the eponymous Greek form of the dynastic name adopted by all epigraphically attested rulers of the 'phil-hellenenic' Arsacid dynasties. The indigenous Parthian and Armenian form was Arshak....

, in order to forestall the Seleucid

Seleucid Empire

The Seleucid Empire was a Greek-Macedonian state that was created out of the eastern conquests of Alexander the Great. At the height of its power, it included central Anatolia, the Levant, Mesopotamia, Persia, today's Turkmenistan, Pamir and parts of Pakistan.The Seleucid Empire was a major centre...

 reconquest of both Parthia

Parthia

Parthia is a region of north-eastern Iran, best known for having been the political and cultural base of the Arsacid dynasty, rulers of the Parthian Empire....

 and Bactria

Bactria

Bactria and also appears in the Zend Avesta as Bukhdi. It is the ancient name of a historical region located between south of the Amu Darya and west of the Indus River...

:

"Soon after, relieved by the death of Diodotus I, Arsaces made peace and concluded an alliance with his son, also by the name of Diodotus; some time later he fought against Seleucos

Seleucus II Callinicus

Seleucus II Callinicus or Pogon , was a ruler of the Hellenistic Seleucid Empire, who reigned from 246 to 225 BC...

 who came to punish the rebels, but he prevailed: the Parthians celebrated this day as the one that marked the beginning of their freedom" (Justin

Junianus Justinus

Justin was a Latin historian who lived under the Roman Empire. His name is mentioned only in the title of his own history, and there it is in the genitive, which would be M. Juniani Justini no matter which nomen he bore.Of his personal history nothing is known...

, XLI,4 )

Around 230 or 223 BC, Diodotus was killed by an usurper, his brother-in-law Euthydemus I

Euthydemus I

Euthydemus I , Greco-Bactrian king in about 230 or 223 BCE according to Polybius., he is thought to have originally been a Satrap of Sogdiana, who overturned the dynasty of Diodotus of Bactria and became a Greco-Bactrian king. Strabo, on the other hand, correlates his accession with internal...

, founder of the Greco-Bactrian Euthydemid dynasty (Polybius

Polybius

Polybius , Greek ) was a Greek historian of the Hellenistic Period noted for his work, The Histories, which covered the period of 220–146 BC in detail. The work describes in part the rise of the Roman Republic and its gradual domination over Greece...

, 11.34, 2).