Drachm 'Black Dirhems Muhammadi ' - citing Caliph al-Amin - Sogdiana 'Transoxiana' Arab-Bukharan

Al-Amin's caliphate lasted only four years before his brother al-Ma'mun defeated and killed him in 813, ending one of the more brutal civil wars the Abbasid dynasty endured. These "Black Dirhems" — so called for their heavily debased billon content relative to earlier silver issues — were a product of that instability, circulating through Transoxiana at a moment when Khorasan's loyalty had already shifted decisively toward al-Ma'mun. The degraded alloy was not accidental carelessness but a fiscal response to war expenditure draining the treasury.

Arab-Bukharan issues of this type represent a transitional coinage absorbing Sogdian minting conventions into the Abbasid administrative framework — a process decades in the making by the time al-Amin's name appeared on them.