Kolkata (Bengali), formerly known as Calcutta, is the capital of the Indian state of West Bengal. Kolkata is the commercial capital of Eastern India, located on the east bank of the Hooghly River. The Kolkata metropolitan area, including suburbs, has a population exceeding 15 million, making it the third most populous metropolitan area in India and the 13th most populous urban area in the world. The city is also classified as the eighth largest urban agglomeration in the world.
Kolkata served as the capital of India during the British Raj until 1911. The city is noted for its revolutionary history, ranging from the Indian struggle for independence to the leftist and trade union movements. Once the centre of modern education, science, culture and politics in India, Kolkata witnessed economic stagnation in the years following India's independence in 1947. However, since the year 2000, an economic rejuvenation has led to an acceleration in the city's growth. Like other metropolitan cities of India, Kolkata continues to struggle with urbanisation problems like poverty, pollution and traffic congestion.