Watch List notes:

ABBASID: al-Ma'mun, 810-833, AR dirham (2.82g), al-Muhammadiya, AH203, A-224, citing 'Ali b. Musa al-Rida, recognized as heir to the caliphate by al-Ma'mun, representing al-Ma'mun's attempt to establish peace and cooperation between the Sunni and Shi'a branches of Islam, also citing the vizier Dhu'l-Ri'asatayn, F-VF.

Estimate: 260-350 USD