25 Rupees Bank of Bengal, Calcutta

The Bank of Bengal was one of the three Presidency Banks established under British colonial administration, and 1857 is about as charged a year as Indian monetary history gets. The Sepoy Mutiny — or the First War of Independence, depending on your framing — erupted that same year, severely disrupting commercial activity across northern India and placing enormous strain on the banking system. Notes of this period circulated under genuinely unstable conditions, not the relatively orderly commerce of earlier decades.

Printed in Calcutta rather than sent to London jobbers, which was unusual for the period and reflects the Presidency Banks' increasing operational self-sufficiency by the mid-nineteenth century. Survivors from this issue are exceptionally rare; most were retired through normal redemption channels, and the chaos of 1857 almost certainly accelerated the destruction of whatever reserves remained uncirculated.