The following year, Mithridates II attacked Adiabene, Gordyene and Osrhoene and conquered these city states, shifting the western border of the Parthian realm to the Euphrates. There the Parthians encountered the Romans for the first time.

In 96 BCE Mithridates II sent one of his officials, Orobazus, as an envoy to Sulla. As the Romans were increasing in power and influence, the Parthians sought friendly relations with the Romans and thus wanted to reach an agreement that assured mutual respect between the two powers. Negotiations followed in which Sulla apparently gained the upper hand, which made Orobazus and the Parthians look like supplicants. Orobazus would later be executed.