Delhi Sultanate, Turk Dynasty, Rukn-ud-din Firuz (AH 633-634/1235 AD), Delhi Mint, Silver Tanka, Obv: The Kalima Shahada on top in two lines and al mustansir billah amir ul mominin at bottom within a double square and koranic verses in margin, Rev: al-sultan al-a’zam Rukn ud dunya wa’l din abu’l muzaffar Firuz Shah bin sultan within  a double square and mint name partly visible in margin, 10.68g, 27.82mm, (G&G # D92), choice very fine, Scarce. 

Firuz was the eldest surviving son of Iltutmish. Weak and irresponsible, he allowed his scheming mother to control him and, as a result, the sultanate began to fall into the hands of various factions. After a reign of only six months, he was seized and executed. All his coins are rare. As with the Dehli Tankas of his father, coins are found with varying amounts of dots in the segments on each side.