'Abbasid Caliphate. Al-Ma'mun, AH 199-218 / AD 813-833. Dirham (Silver, 21 mm, 2.81 g, 9 h), citing ʿAlī ibn Mūsā al-Riḍā as heir and the vizier Dhū al-Riyāsatayn, Samarqand, AH 202 = AD 817/8. Central field, in four lines: lā ilāha illā / Allāh waḥdahū / lā sharīka lahū / al-mashriq (‘There is no deity but God alone; He has no associate / the East’ in Arabic). Inner margin: bi-sm Allāh ḍuriba hādhā al-dirham bi-Samarqand sanat ithnatayn wa-miʾatayn (‘In the name of God, this dirham was struck in Samarqand in the year two hundred and two’ in Arabic). Outer margin (Qurʾān 30:3-4): li-llāh al-amr min qabl wa-min baʿd wa-yawmaʾidhin yafraḥ al-muʾminūn (‘To God belongs the command before and after, and on that day the believers will rejoice’ in Arabic). Rev. Central field, in seven lines: li-llāh / Muḥammad rasūl Allāh / al-Maʾmūn khalīfat Allāh / mimmā amara bihī al-amīr al-Riḍā / walī ʿahd al-muslimīn ʿAlī ibn Mūsā / ibn ʿAlī ibn Abī Ṭālib / Dhū al-Riyāsatayn (‘For God / Muḥammad is the Messenger of God / al-Maʾmūn, the Caliph of God / from that ordered by the amīr al-Riḍā / heir to the covenant of the Muslims, ʿAlī ibn Mūsā / son of ʿAlī ibn Abī Ṭālib / Dhū al-Riyāsatayn’ in Arabic). Margin (Qurʾān 9:33): Muḥammad rasūl Allāh arsalahu bi-l-hudā wa-dīn al-ḥaqq li-yuẓhirahu ʿalā al-dīn kullihi wa-law kariha al-mushrikūn (‘Muḥammad is the Messenger of God, whom He sent with guidance and the religion of truth to make it prevail over all religion, even though the polytheists may dislike it’ in Arabic). Album 224. Lowick/Savage 2678. SCC 1165. SICA III, 912–913. Very rare, of great interest and nicely toned. Some marks on the obverse and small areas of weakness, otherwise, nearly extremely fine.



This historically important issue was struck after al-Maʾmūn appointed ʿAlī ibn Mūsā al-Riḍā, the eighth Imām of Twelver Shiʿism, as heir to the caliphate in AH 201 / AD 817. The appointment was part of al-Maʾmūn’s attempt to reconcile ʿAbbāsid authority with Alid legitimacy, but it provoked strong opposition among Abbasid circles, especially in Iraq. The coinage naming al-Riḍā as walī ʿahd al-muslimīn is therefore one of the clearest surviving official records of this extraordinary political experiment.

The reverse legend is remarkable for the fullness of al-Riḍā’s titulature and genealogy: al-amīr al-Riḍā walī ʿahd al-muslimīn ʿAlī ibn Mūsā ibn ʿAlī ibn Abī Ṭālib. By tracing him explicitly to ʿAlī ibn Abī Ṭālib, the inscription places his Alid descent at the center of his political legitimacy. This makes the type especially significant for both ʿAbbāsid and Shiʿite numismatics.

The final line names Dhū al-Riyāsatayn, the powerful vizier al-Faḍl ibn Sahl, whose title means ‘holder of the two offices’. His presence on the coin reflects the influence of al-Maʾmūn’s eastern court in Khurāsān and the political faction behind the designation of al-Riḍā as heir. Most Samarqand AH 202 varieties naming al-Riḍā also cite Dhū al-Riyāsatayn.

Coins naming Imām al-Riḍā are among the most historically charged and desirable issues of the ʿAbbāsid silver series, with an always-strong demand.