 On 20 December 1757, the then new Nawab of Bengal, Mir Zafar assigned the East India Company zamindari rights over the Zamindari of Calcutta.In 1759, Robert Clive received as a "jagir" the Zamindari of Calcutta as a result of services rendered in quelling rebellion of the Nawab's eldest son, Shah Alam.In 1765, another grant which received the Nawab's approval gave unconditional proprietary rights of the 24 Parganas for 10 years following which it the proprietary rights would go to the East India Company.