Tetradrachm - Arsaces XVI monograms above and below bow

Sellwood 30.9 belongs to the reign of Phraates III, who came to power around 70 BC after a period of dynastic chaos that saw multiple claimants eliminate one another. His timing was shrewd: both Lucullus and later Pompey actively courted Parthian neutrality during Rome's wars against Mithridates VI of Pontus, and Phraates played both sides with considerable skill, extracting diplomatic recognition of the Euphrates as a boundary without committing troops to either Roman faction.

The billon fabric of this issue reflects a gradual debasement that had been creeping into Parthian tetradrachms across the preceding generation.