Persia (Post-Mongol). Aq Qoyunlu. 'Ali, AH 839-841 / AD 1435-1438. 1/3 Tanka (Silver, 15 mm, 1.33 g, 11 h), Kemah. Within a square, ‘lā ilāha illā / Allāh Muḥammad / rasūl Allāh’ (‘There is no deity but Allah. Muhammad is the messenger of Allah’ in Arabic); the names of the four Rashidun Caliphs in Arabic in the four surrounding panels, two of them off flan: Abūbakr / ʿUmar / ʿUthmān / ʿAlī. Rev. Within a central circle, ‘ḍarb Kimākh’ (‘Struck in Kemah’ in Arabic); citing the Timurid Shahrukh (AH 807-850 / AD 1405-1447 AD) in the margin, ‘khalaf(?) mīrzā(?) al-sulṭān al-aʿẓam Shāhrukh Bahādur khalada mulkuhū’ (‘Deputy of the mirza, the supreme sultan Shahrukh Bahadur. May his kingdom be perpetuated’ in Arabic). Album -. Zeno 304963. Extremely rare. Some die breaks and flan faults on the edge, otherwise, very fine.