Pre-reform issues, Tabaristan ('Abbasid governors). Umar b. al-'Ala. AH 155-165 / AD 771-780. AR Hemidrachm (23.2mm, 1.89 g, 8h). TPWRSTAN (Tabaristan) mint. Dated PYE 129 = AH 164 (AD 780/1). Pellet above S of mint-name. Malek 80.2; Album 56. Superb EF.