King Mithridates VI of Pontus, who conflicted with Rome and sought to oust it from Asia Minor, sent ambassadors to Tigran II with a proposal to conclude an alliance. The union with the powerful Kingdom of Pontus, which was enforced by the marriage between Tigran the Great and Mithridates VI Eupator’s daughter Cleopatra, was beneficial to Armenia.
The allies agreed to seize the Kingdom of Cappadocia. In 93 BC, this kingdom was captured by Armenian troops. After some time, in order to avoid military clashes with the Roman Republic, Tigran the Great withdrew his troops from Cappadocia.
At its southeastern borders, Greater Armenia was resisted by the Parthian Kingdom, which at that time included Media Atropatene and Northern Mesopotamia. After the death of the king of Parthia, who was married to Tigran’s daughter, in 87 BC, Armenian troops occupied Media Atropatene and then invaded Parthia.
Pursuing the Parthian army, the troops of Tigran II approached the city of Ecbatana, one of the residences of the kings of Parthia. Intimidated by the success of Tigran the Great, the Parthian king hurried to make peace, under the terms of which he was to transfer the territory of Atropatene and Northern Mesopotamia to Tigran II’s kingdom.
The king of Parthia also surrendered his title “King of Kings” to the Armenian king. This title would be minted on Armenian coins with the image of King Tigran the Great.