Silver rupee of Sher Shah Suri (1538-1545), 949AH, Jahanpanah mintless type, probably from Shergarh mint, Delhi Sultanate (D-812)

Sher Shah al-sultan-hallada allah mulkahu wa siltanahu and a date within a circle, Nagari legends in the lower part of the circular margin / Shahada within a circle and al-sultan al-adil in the margin. Dated to 949 AH = 1542 AD. 29.5mm, 11.09 grams.  Shergarh (or some other city in Bihar) mint. "The coins of Indian Sultanates" #D812; Rajgor 1691; Wight 1078.

Rare type, quite difficult to find. 

Sher Shah Suri (1486 22 May 1545) was the founder of the Sur Empire in North India, with its capital at Delhi. An ethnic Pashtun, Sher Shah took control of the Mughal Empire in 1540. After his accidental death in 1545, his son Islam Shah became his successor. He first served as a private before rising to become a commander in the Mughal army under Babur and then as the governor of Bihar. In 1537, when Babur's son Humayun was elsewhere on an expedition, Sher Khan overran the state of Bengal and established the Sur dynasty. A brilliant strategist, Sher Shah proved himself a gifted administrator as well as an able general. His reorganization of the empire laid the foundations for the later Mughal emperors, notably Akbar the Great, son of Humayun.