Watch List notes:

ABBASID: al-Ma'mun, 810-833, AR dirham (2.89g), Samarqand, AH202, A-224, citing the Shi'ite Imam 'Ali b. Musa al-Rida as heir-apparent to the caliphate, al-Ma'mun's attempt to unify Sunni and Shi'ite Islam, choice EF, R.

Estimate: 600- 700 USD