Tigranes The Great, a king of Armenia, ascended the throne about 96 B. C, died about 55. He was a descendant of Artaces, the reputed founder of the Armenian monarchy, and by wars during the early part of his reign united all Armenia under his rule, and conquered in addition several provinces. He also acquired by his war with Parthia two important provinces, which comprised the whole of northern Mesopotamia and the tract east of the Middle Tigris, including Assyria proper and Arbelitis; and by some unknown means he obtained possession also of Media Atropatene. In 83 he was invited into Syria by the inhabitants, who were wearied with the continual strife between the princes of the house of the Seleueidae, and he established himself as king over Cilicia, Syria, and most of Phoenicia, residing at Nisi-bis. About 80 he made the strongly fortified city of Tigranocerta, between the Tigris and Lake Van, his capital. His support of Mithridates of Pontus, his father-in-law, involved him in a war with the Romans. Lucullus gained several victories over them, and captured Tigranocerta. Pompey, his successor, made an alliance with Phraates III. of Parthia, who engaged Tigranes in war on his own frontier, while Pompey marched into Pontus. The occasion for it was offered by the eldest son of Tigranes, of the same name, who had engaged in a conspiracy against the life of his father, and being discovered had fled to Phraates, who readily embraced his cause and marched an army into Armenia. Tigranes fled, Artaxata was invested, and the Parthian monarch withdrew, leaving the young Tigranes as many troops as he thought necessary to press the siege to a successful issue.

When Phraates was gone, Tigranes returned, defeated his son, and drove him out of his kingdom. But soon afterward he was forced to submit to Pompey, who in the mean time had defeated Mithridates also. (See Mithridates.) Tigranes went to the camp of Pompey, and placed himself as a suppliant at the feet of that general. Pompey would not accept the diadem which he offered him, and treated him in a friendly manner, placing him on the throne of Armenia proper. At first Pompey destined the province of Gordyene for the younger Tigranes, but that prince offending him, he made it over to Ariobarzanes of Cappadocia. As the province gave rise to disputes between Tigranes and Phraates, Pompey sent Afranius to drive the Parthians out of it, and gave it to the Armenians. In 64 Tigranes was again at war with the king of Parthia, but the differences between them were composed by the intervention of Pompey. After this he disappears almost entirely from history. He was succeeded by his son Artavasdes or Ardavast.