Tigranes II, more commonly known as Tigranes the Great (140 – 55 BC) was King of Armenia under whom the country became, for a short time, the strongest state to Rome's east. He was a member of the Artaxiad Royal House. Under his reign, the Armenian kingdom expanded beyond its traditional boundaries, allowing Tigranes to claim the title Great King, and involving Armenia in many battles against opponents such as the Parthian and Seleucid empires, and the Roman Republic.

In approximately 120 BC, the Parthian king Mithridates II (r. 124–91 BC) invaded Armenia and made its king Artavasdes I acknowledge Parthian suzerainty. Artavasdes I was forced to give the Parthians Tigranes as a hostage, who was either his son or nephew. Tigranes lived in the Parthian court at Ctesiphon, where he was schooled in Parthian culture. Tigranes remained a hostage at the Parthian court until c. 96/95 BC, when Mithridates II released him and appointed him as the king of Armenia. Tigranes ceded an area called "seventy valleys" in the Caspiane to Mithridates II, either as a pledge or because Mithridates II demanded it Tigranes' daughter Ariazate had also married a son of Mithridates II, which has been suggested by the modern historian Edward Dąbrowa to have taken place shortly before he ascended the Armenian throne as a guarantee of his loyalty. Tigranes would remain a Parthian vassal until the end of the 80's BC.

When he came to power, the foundation upon which Tigranes was to build his Empire was already in place, a legacy of the founder of the Artaxiad Dynasty, Artaxias I, and subsequent kings. The mountains of Armenia, however, formed natural borders between the different regions of the country and as a result, the feudalistic nakharars had significant influence over the regions or provinces in which they were based. This did not suit Tigranes, who wanted to create a centralist empire. He thus proceeded by consolidating his power within Armenia before embarking on his campaign.

He deposed Artanes, the last king of the Kingdom of Sophene and a descendant of Zariadres.