Bengal Sultanate, Nasir Al-Din Mahmud Shah (AH 837-864, 1433/34-1459 AD), Silver Tanka, Lion type, 10.26 gms, Unread Mint, AH 849, Obv. Lion to left, ruler's titles around, Rev. al-muayyad bi-tayid al-rahman khalifat allah bi'l hujjat wa'l burhan, G&G #B481, very fine, extremely rare. Note: On the reverse, the coin's legend conveys a profound theological assertion of power: The Sultan proclaims that his sovereign authority, military victories, and temporal might do not derive from human agency alone, but are actively sustained by divine mandate(Allah) and caliphal legitimization, substantiated by manifest proofs & evidences. Concurrently, the introduction of the lion emblem to the coinage in AH 849 likely signified a momentous political triumph, rapid territorial consolidation, or an explicit declaration of paramount sovereignty. While extant contemporary chronicles remain silent regarding a specific battlefield victory during this exact year, the numismatic iconography strongly implies a watershed moment in the regime's assertion of authority.