Ancient States Did Not Maintain Permanent Embassies

More than two decades passed between the meeting of Sulla and Orobazus [in 96 B.C.E.] and the next diplomatic contact between Rome and Parthia. Ancient states did not maintain permanent embassies in each other’s capitals or feel the need to be in constant touch, and instead sent ambassadors only when there was something that they wished to say. Preoccupied with bitter internal strife and with enemies and friends closer to their territory, neither the Romans nor Parthians chose to seek out the other.

— Rome and Persia, pp. 63