The Great Bengal famine of 1770 (Bengali: ৭৬-এর মন্বন্তর, Chhiattōrer monnōntór; lit The Famine of '76) was a catastrophic famine between 1769 and 1773 (1176 to 1180 in the Bengali calendar) that affected the lower Gangetic plain of India. The famine is estimated to have caused the deaths of 10 million people, reducing the population to thirty million in Bengal, which included Bihar and parts of Odisha. The Bengali name derives from its origins in the Bengali calendar year 1176. ("Chhiattōr"- "76"; "monnōntór"- "famine" in Bengali). It was caused due to the widespread forced cultivation of opium (forced upon local farmers by the British East India Company as part of its strategy to export it to China) in place of local food crops, resulting in a shortage of grain for local people in Bengal.