Tigranes, the king, fled at his approach, and betook himself to the neighboring mountains.

Artaxata was invested; but as the siege promised to be long, the Parthian monarch after a time withdrew, leaving the pretender with as many troops as he thought necessary to press the siege to a successful issue.

The result, however, disappointed his expectations.

Scarcely was Phraates gone, when the old king fell upon his son, defeated him, and drove him beyond his borders.
He was forced, however, soon afterwards, to submit to Pompey, who, while the civil war was raging in Armenia, had defeated Mithridates and driven him to take refuge in the Tauric Chersonese.
Phraates, now, naturally expected the due reward of his services, according to the stipulations of his agreement with Pompey.

But that general was either dissatisfied with the mode in which the Parthian had discharged his obligations, or disinclined to strengthen the power which he saw to be the only one in these parts capable of disputing with Rome the headship of Asia.