Al-Imam Amir al-Muminin al-Munstasir in a double square within a circle with no annulets, marginal legend giving the name of the Mint (Khitta Lakhnauti) and spelling out the date (720 AH =  1320 AD) // Al-sultan al-azzam shams al-dunya wa'l din abu'l muzzafar Firuz shah al-Sultan  in a double square within a circle with no annulets. 30mm, 11.0 grams. Mint of Khitta Lakhnauti. "The Coins of the Indian Sultanates"B98.

EXTREMELY rare struck on such a huge flan with full marginal legends! 

The Sultanate of Bengal was based in Bengal for much of the 14th, 15th and 16th centuries. Its imperial capital was one of the world's largest cities, which had a circle of vassal states, including Odisha in the southwest, Arakan in the southeast, and Tripura in the east. In 1494, the Bengal Sultanate reached the peak of its territorial growth with control over Kamrup and Kamata. The empire was known as one of the major trading nations of the medieval world. It was defeated by Suris and then by the Mughals and absorbed into the Mughal Empire in the 16th century.