Arab Sasanian: 'Uthman ibn 'Affan, Rashidun caliph (644-656), silver dirham/drachm (2.70g), SK (Sijistan) mint, YE 20 (AH 30-31 / 651-652 CE). In name of Yazdigerd. First definitive coin in Islamic history.

Arab Sasanian: 'Uthman ibn 'Affan, Rashidun caliph (644-656), silver dirham/drachm (2.70g), SK (Sijistan) mint, YE 20 (AH 30-31 / 651-652 CE). Anonymous type struck in the name of Yazdigerd. Arabic "bismillah" (in the name of Allah) in obverse margin. Album 1 (R), Malek p. 586. Clipped to Umayyad post-reform weight standard. Some strike weakness, otherwise fine. This is the first definitive coin in Islamic history, imitating the drachmas of the last Sasanian king Yazdigerd III with the addition of the Arabic "bismillah" (in the name of Allah) in the obverse margin. Dated during the reign of the Rashidun caliph and companion 'Uthman ibn 'Affan.