Pacorus II ruled intermittently — his reign was interrupted repeatedly by rival claimants, and the coinage reflects this instability. Sellwood type 76 is among the later Parthian tetradrachms struck on increasingly debased billon flans, a debasement that accelerated through the final decades of Arsacid rule as the dynasty's grip on Mesopotamia weakened under pressure from both internal pretenders and Roman encroachment on the western frontier.
The "uncertain month" designation in Sellwood 76.1 indicates the Seleucid month control mark is either absent or illegible on the flan — a common condition for this type, not a strike anomaly.
Pacorus II ruled intermittently — his reign was interrupted repeatedly by rival claimants, and the coinage reflects this instability. Sellwood type 76 is among the later Parthian tetradrachms struck on increasingly debased billon flans, a debasement that accelerated through the final decades of Arsacid rule as the dynasty's grip on Mesopotamia weakened under pressure from both internal pretenders and Roman encroachment on the western frontier.
The "uncertain month" designation in Sellwood 76.1 indicates the Seleucid month control mark is either absent or illegible on the flan — a common condition for this type, not a strike anomaly.