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
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
First Contact between the Romans and the Parthians
When Sulla in following out his expedition arrived in the region of the Euphrates, in whose waters the Roman standards were then first mirrored, the Romans came for the first time into contact with the Parthians, who in consequence of the variance between them and Tigranes had occasion to make approaches to the Romans. On both sides there seemed a feeling that it was of some moment, in this first contact between the two great powers of the east and the west, that neither should renounce its claims to the sovereignty of the world; but Sulla, bolder than the Parthian envoy, assumed and maintained in the conference the place of honour between the king of Cappadocia and the Parthian ambassador.
Sulla's fame was more increased by this greatly celebrated conference on the Euphrates than by his victories in the east; on its account the Parthian envoy afterwards forfeited his life to his masters resentment. But for the moment this contact had no further result. Nicomedes in reliance on the favour of the Romans omitted to evacuate Paphlagonia, but the decrees adopted by the senate against Mithradates were carried further into effect, the reinstatement of the Scythian chieftains was at least promised by him; the earlier status quo in the east seemed to be restored (662).
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/4-08-east-king-mithradates.asp?pg=30