Kolkata, formerly Calcutta, is the capital of the Indian state of West Bengal. It is located in eastern India on the east bank of the River Hooghly. When referred to as Calcutta, it usually includes the suburbs, and thus its population exceeds 15 million, making it India's third-largest metropolitan area and urban agglomeration as well as the world's 8th largest agglomeration.

Kolkata served as the capital of India during the British Raj until 1911. Once the centre of modern education, industry, science, culture and politics in India, Kolkata has witnessed intense political violence, clashes and economic stagnation since 1954. Since the year 2000, economic rejuvenation has spurred on the city's growth. Like other metropolitan cities in India, Kolkata continues to struggle with the problems of urbanisation: poverty, pollution and traffic congestion.

Kolkata is noted for its revolutionary history, ranging from the Indian struggle for independence to the leftist and trade union movements.