Khwarizmshahs. Jalal al-Din Mangubarni. AH 617-628 / AD 1220-1231. AR Dirham (17.8mm, 3.16 g, 9h). Qal'at Nay mint. Undated (struck circa AH 617-622). Obverse field: Jalal al-dunya / wa'l-din Mangubarni / bin al-Sultan / Reverse field: Qal'at Nay / al-Nasir li-din / Allah amir al-mu'- / minin. Album 1743A. Iridescent toning. Near EF. Rare.
Qal'at Nay was a mountaintop fortress to the west of Ghazna. It was only active as a mint under Mangubarni. While the present coin is undated (as are all published coins from this mint), it must have been issued between the accession of Mangubarni in AH 617 and the death of the caliph al-Nasir in AH 622.