Persia (Post-Mongol). Timurids. Shah Rukh I, AH 807-850 / AD 1405-1447. 1/3 Tanka (Silver, 12 mm, 1.39 g, 11 h), 5th series, Erzincan, undated. 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, three of them off flan: ‘[Abūbakr] / ʿUmar / [ʿUthmān / ʿAlī]’. Rev. Within a central circle, ‘ḍarb / Arzanjān’ (‘Struck in Erzincan’ in Arabic); in the margin, ‘al-sulṭān … khallada Allāh mulkahū’ (‘Sultan … May Allah perpetuate his kingdom’ in Arabic). Album A2407. Very rare. Minor doubling and tiny deposits, otherwise, nearly extremely fine.