At the former was stationed the great-king, who had shortly before returned from Syria, after having temporarily deferred the prosecution of his plans of conquest on the Mediterranean on account of the embroilment with the Romans.

He was just projecting an inroad into Roman Asia from Cilicia and Lycaonia, and was considering whether the Romans would at once evacuate Asia or would previously give him battle, possibly at Ephesus, when the news was brought to him of the advance of Lucullus, which threatened to cut off his communications with Artaxata.

He ordered the messenger to be hanged, but the disagreeable reality remained unaltered; so he left the new capital and resorted to the interior of Armenia, in order there to raise a force--which had not yet been done--against the Romans.
Meanwhile Mithrobarzanes with the troops actually at his disposal and in concert with the neighbouring Bedouin tribes, who were called out in all haste, was to give employment to the Romans.

But the corps of Mithrobarzanes was dispersed by the Roman vanguard, and the Arabs by a detachment under Sextilius; Lucullus gained the road leading from Tigranocerta to Artaxata, and, while on the right bank of the Tigrisa Roman detachment pursued the great-king retreating northwards, Lucullus himself crossed to the left and marched forward to Tigranocerta.
Siege and Battle of Tigranocerta The exhaustless showers of arrows which the garrison poured upon the Roman army, and the setting fire to the besieging machines by means of naphtha, initiated the Romans into the new dangers of Iranian warfare; and the brave commandant Mancaeus maintained the city, till at length the great royal army of relief had assembled from all parts of the vast empire and the adjoining countries that were open to Armenian recruiting officers, and had advanced through the north-eastern passes to the relief of the capital.
The leader Taxiles, experienced in the wars of Mithradates, advised Tigranes to avoid a battle, and to surround and starve out the small Roman army by means of his cavalry.

But when the king saw the Roman general, who had determined to give battle without raising the siege, move out with not much more than 10,000 men against a force twenty times superior, and boldly cross the river which separated the two armies; when he surveyed on the one side this little band, "too many for an embassy, too few for an army," and on the other side his own immense host, in which the peoples from the Black Sea and the Caspian met with those of the Mediterranean and of the Persian Gulf, in which the dreaded iron-clad lancers alone were more numerous than the whole army of Lucullus, and in which even infantry armed after the Roman fashion were not wanting; he resolved promptly to accept the battle desired by the enemy.
But while the Armenians were still forming their array, the quick eye of Lucullus perceived that they had neglected to occupy a height which commanded the whole position of their cavalry.