Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
He found the Parthian war already commenced. The faithless conduct
of Pompeius towards the Parthians has been already mentioned;(1)
he had not respected the stipulated frontier of the Euphrates
and had wrested several provinces from the Parthian empire
for the benefit of Armenia, which was now a client state of Rome.
1. iv. 434
King Phraates had submitted to this treatment; but after he had been
murdered by his two sons Mithradates and Orodes, the new king
Mithradates immediately declared war on the king of Armenia, Artavasdes,
son of the recently deceased Tigranes (about 698).(2)
2. Tigranes was still living in February 698 (Cic. pro Sest. 27,
59); on the other hand Artavasdes was already reigning before 700
(Justin, xlii. 2, 4; Plut. Crass. 49).
