Plutarch Lucullus 26

[1] Thus successful in his campaign, Lucullus struck camp and proceeded to Tigranocerta, which city he invested and began to besiege. There were in the city many Greeks who had been transplanted, like others, from Cilicia, and many Barbarians who had suffered the same fate as the Greeks,—Adiabeni, Assyrians, Gordyeni, and Cappadocians, whose native cities Tigranes had demolished, and brought their inhabitants to dwell there under compulsion.

[2] The city was also full of wealth and votive offerings, since every private person and every prince vied with the king in contributing to its increase and adornment. Therefore Lucullus pressed the siege of the city with vigour, in the belief that Tigranes would not endure it, but contrary to his better judgment and in anger would descend into the plains to offer battle; and his belief was justified.

[3] Mithridates, indeed, both by messengers and letters, strongly urged the king not to join battle, but to cut off the enemy’s supplies with his cavalry; Taxiles also, who came from Mithridates and joined the forces of Tigranes, earnestly begged the king to remain on the defensive and avoid the invincible arms of the Romans. And at first Tigranes gave considerate hearing to this advice.

[4] But when the Armenians and Gordyeni joined him with all their hosts, and the kings of the Medes and Adiabeni came up with all their hosts, and many Arabs arrived from the sea of Babylonia, and many Albanians from the Caspian sea, together with Iberians who were neighbours to the Albanians; and when not a few of the peoples about the river Araxes, who are not subject to kings, had been induced by favours and gifts to come and join him; and when the banquets of the king, and his councils as well, were full of hopes and boldness and barbaric threats,—then Taxiles ran the risk of being put to death when he opposed the plan of fighting, and Mithridates was thought to be diverting the king from a great success out of mere envy.

[5] Wherefore Tigranes would not even wait for him, lest he share in the glory, but advanced with all his army, bitterly lamenting to his friends, as it is said, that he was going to contend with Lucullus alone, and not with all the Roman generals put together. And his boldness was not altogether that of a mad man, nor without good reason, when he saw so many nations and kings in his following, with phalanxes of heavy infantry and myriads of horsemen.

[6] For he was in command of twenty thousand bowmen and slingers, and fifty-five thousand horsemen, of whom seventeen thousand were clad in mail, as Lucullus said in his letter to the Senate; also of one hundred and fifty thousand heavy infantry, some of whom were drawn up in cohorts, and some in phalanxes; also of road-makers, bridge-builders, clearers of rivers, foresters, and ministers to the other needs of an army, to the number of thirty-five thousand. These latter, being drawn up in array behind the fighting men, increased the apparent strength of the army.