West Bengal (, Bengali: Poshchim Bongo, , abbr. WB) is a state in the eastern portion of India. It is situated along the Bay of Bengal, along with a population of over 91 million inhabitants within an area of . 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 Odisha, Jharkhand, 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 Gauḍa 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 conquered by the British East India Company at the Battle of Plassey in 1757 and became part of the Bengal Presidency. From 1772 to 1911, Calcutta was the capital of British India. From 1912 to India's Independence in