Direct Action Day was the day the All-India Muslim League decided to take "direct action" for a separate Muslim homeland after the British exit from India. Also known as the 1946 Calcutta Killings, it was a day of nationwide communal riots. It led to large-scale violence between Muslims and Hindus in the city of Calcutta in the Bengal province of British India. The day also marked the start of what is known as The Week of the Long Knives. While there is a certain degree of consensus on the magnitude of the killings, including their short-term consequences, controversy remains regarding the exact sequence of events, the various actors' responsibility and the long-term political consequences.

Kolkata, or, , Bengali: [kolˈkata], IAST: Kōlkātā also known as Calcutta, is the capital and largest city of the Indian state of West Bengal. It lies on the eastern bank of the Hooghly River, 80 km (50 mi) west of the border with Bangladesh. It is the primary financial and commercial centre of eastern and northeastern India. Kolkata is the seventh most populous city of India with an estimated city proper population of 4.5 million (0.45 crore). It is the centre of the Kolkata Metropolitan Region, one of the most populous metropolitan areas in the world with a population of over 15 million residents. Kolkata is the de facto cultural capital of India and a historically and culturally significant city in the historic region of Bengal. It is the second largest Bengali-speaking city in the world. It has the highest number of Nobel laureates among all cities in India.