Bengal Sultanate, Silver Tanka, 10.56gm, INO Rukn Al Din Firuz (Delhi Sultan) (AH 633 / AD 1235). AH 633, Lakhnauti Mint, Obv: Titles, Rev: Fi ahad legend and caliph al Mustansir. G&G B53. Fine+, Very Rare. This coin was struck in the name of Firuz by the governor Izz al din Tughral Tughan Khan in lakhnauti, but Firuz survived for six months only, and these coins were withdrawn from circulation. View Lot Details