West Bengal is a state in the eastern portion of India. It is situated along the Bay of Bengal. It had a population of over 91 million inhabitants within an area of 88,752 km (34,267 sq mi) as of 2011. The population estimate as of 2023 is 99,723,000. West Bengal is the fourth-most populous and thirteenth-largest state by area in India, as well as the eighth-most populous country subdivision of the world. As a part of the Bengal region of the Indian subcontinent, it borders Bangladesh in the east, and Nepal and Bhutan in the north. It also borders the Indian states of Jharkhand, Odisha, Bihar, Sikkim and Assam. The state capital is Kolkata, the third-largest metropolis, and seventh largest city by population in India. West Bengal includes the Darjeeling Himalayan hill region, the Ganges delta, the Rarh region, the coastal Sundarbans and the Bay of Bengal. The state's main ethnic group are the Bengalis, with the Bengali Hindus forming the demographic majority.
The area's early history featured a succession of Indian empires, internal squabbling, and a tussle between Hinduism and Buddhism for dominance. Ancient Bengal was the site of several major Janapadas, while the earliest cities date back to the Vedic period. The region was part of several ancient pan−Indian empires, including the Vangas, Mauryans, and the Guptas. The citadel of Gauḍa served as the capital of the Gauda kingdom, the Pala Empire, and the Sena Empire. Islam was introduced through trade with the Abbasid Caliphate, but following the Ghurid conquests led by Bakhtiyar Khalji and the establishment of the Delhi Sultanate, the Muslim faith spread across the entire Bengal region. During the Bengal Sultanate, the territory was a major trading nation in the world, and was often referred by the Europeans as the "richest country to trade with". It was absorbed into the Mughal Empire in 1576. Simultaneously, some parts of the region were ruled by several Hindu states, and Baro-Bhuyan landlords, and part of it was briefly overrun by the Suri Empire. Following the death of Emperor Aurangzeb in the early 1700s, the proto-industrialised Mughal Bengal became a semi-independent state under the Nawabs of Bengal, and showed signs of the first Industrial Revolution. The region was later annexed into the Bengal Presidency by the British East India Company after the Battle of Buxar in 1764. From 1772 to 1911, Calcutta was the capital of all of East India Company's territories and then the capital of the entirety of India after the establishment of the Viceroyalty. From 1912 to India's Independence in 1947, it was the capital of the Bengal Province.