Sultans of Bengal, Nasir al-Din Mahmud Shah (1433-1459 AD), silver tanka, Muhammadabad mint, AH 864, G&G Unrecorded , 10.54g. Obv: Legend in scalloped circle Nasir al-Dunya wa al-Din Mahmud Shah Sultan. Rev: Legend in ornamented circle Ghauth al Islam wa al-Muslimeen, followed by the mintname. Very fine, Rare.The reading of the mint name is not certain.