Watch List notes:

ABBASID: al-Ma 'mun, 810-833, AR dirham, (2.92gm, 26mm) Madinat Isbahan, AH202, A-224, citing 'Ali b. Musa al-Rida, recognized as heir 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, Good Very Fine and Very Rare.