1/2 Drachm - 'Umar b. al-'Ala Abbasid Governors of Tabaristan - Arab-Sasanian

Tabaristan — the mountainous region south of the Caspian Sea — resisted full Islamicization long after the Arab conquests, and its coinage reflects that friction directly. The governors appointed by the Abbasid caliphate continued issuing fractional silver in the old Sasanian half-drachm module well into the eighth century, a practical concession to a population that trusted familiar monetary forms. 'Umar b. al-'Ala governed the region for an exceptionally long stretch, and his name appears on more Tabaristan issues than virtually any other governor in the series.

The Tabaristan hemidrachm series is one of the few places where Sasanian monetary tradition survived intact under Islamic administration — Baghdad tolerated it because the alternative was no coinage at all in a region barely under control.