The Kingdom of Sophene was ruled by the
Orontids, a dynasty of
Iranian origin. They were descended from
Orontes I, a
Bactrian nobleman who was the son-in-law of the
Achaemenid King of Kings Artaxerxes II (). According to the
Geographica of the Greek writer
Strabo (died 24 CE), Sophene first emerged as a distinct kingdom under
Zariadres (), who was installed as its ruler by the Seleucid king
Antiochus III the Great (). He further adds that following the defeat of Antiochus III against the
Romans, Zariadres declared independence. However this report is strongly contradicted by epigraphic and numismatic evidence. Sophene most likely emerged as distinct kingdom in the 3rd century BC, during the gradual decline of Seleucid influence in the Near East and the split of the Orontid dynasty into several branches. Three rulers belonging to a different Orontid branch,
Sames I,
Arsames I and
Xerxes ruled the western part of Greater Armenia, perhaps from
Commagene to
Arzanene. Following the death of Zariadres, his son
Artaxias I claimed the right to rule over Sophene based on his succession rights (
primogeniture). However, the younger line in Sophene managed to preserve the independence of their kingdom, due to their diplomatic (and possibly dynastic) link with
Cappadocia. Three known successors of Zariadres are known, which were
Mithrobouzanes,
Arkathias, and Arsakes. The kingdom's capital was
Carcathiocerta, identified as the now abandoned town-site of
Eğil on the Tigris River north of
Diyarbakir. However, its largest settlement and only true city was
Arsamosata, located further to the north. Arsamosata was founded in the 3rd century BCE and survived in a contracted state until perhaps the early 13th century CE. Sophene was autonomous for the majority of the 2nd century BCE. Change first occurred with the arrival of the
Parthian Empire, who under the
King of Kings Mithridates II () forced Sophene to recognize their suzerainty. Sophene was conquered by the King of Greater Armenia, Tigranes II the Great , but Tigranes lost control over Sophene during his war with Rome. After Tigranes II was defeated by the Romans,
Pompey installed Tigranes' son
Tigranes the Younger as ruler of Sophene, then ceded the kingdom to
Ariobarzanes I of Cappadocia. It is debated whether after 66 BCE Sophene came back under Greater Armenian control or became a part of Cappadocia. Around 54 CE, the Romans installed
Sohaemus of Emesa as King of Sophene. After this, Sophene reverted to Armenian control and was ruled as an
Armenian province. Branches of the
Orontid dynasty continued to rule parts of Sophene after it was annexed by Greater Armenia. == Religion and culture ==