In the 3d cent. B.C., Bengal belonged to the empire of Asoka. It became a political entity in the 8th cent. A.D. under the Buddhist Pala kings. In the 11th cent. the Hindu Sena dynasty arose from the remnants of the Pala empire. Bengal was conquered (c.1200) by Muslims of Turki descent. When the Portuguese began their trading activities (late 15th cent.), Bengal was a part of the Muslim Mughal empire. The British East India Company established its first settlement in 1642 and extended its occupation by conquering the native princes and expelling the Dutch and French. Muslim control of Bengal ended with the defeat of Siraj-ud-Daula by British forces under Robert Clive at the Battle of Plassey in 1757.

Under British control, Bengal was a presidency of India. At various times the neighboring provinces of Assam, Bihar, Jharkhand, and Orissa were administered under the Bengal presidency. In 1905, Bengal was split into two provinces. The population, which speaks mainly Bengali, is ethnically quite homogeneous but is almost equally divided between Muslims and Hindus. When India was partitioned in 1947, the province was divided along the line approximately separating the two main concentrations of the religious communities.

East Bengal, overwhelmingly Muslim in population, became East Pakistan in 1947 and the independent nation of Bangladesh in 1971. West Bengal (2001 provisional pop. 80,221,171), 33,928 sq mi (87,874 sq km), with its capital at Kolkata (Calcutta), became a state of India. It is bordered by Bangladesh and the state of Assam on the east; Nepal, Bhutan, and the state of Sikkim on the north; the Indian states of Bihar, Jharkhand, and Orissa on the west; and the Bay of Bengal on the south. A highly industrialized region, it has jute mills, steel-fabricating plants, and chemical industries, all mainly centered in the Hugliside industrial complex. Coal is mined and petroleum is refined.

In 1950, West Bengal absorbed the state of Cooch Behar. In the 1970s disputes between Hindus and Muslims, further complicated by droves of refugees from Bangladesh (formerly East Pakistan) and agitation by Maoist groups called Naxalites, created political instability. The 1980s saw an uprising by Gurkhas in the Darjeeling area, which became a semiautonomous district; some Gurkhas have continued to demand a separate state. Maoist rebels experienced a resurgence in the state in late 2008 and seized control of the region around Lalgarh, where farmers opposed the building of a steel plant; paramilitary forces moved in June, 2009, to regain control of the area. West Bengal is governed by a chief minister and cabinet responsible to a bicameral legislature with one elected house and by a governor appointed by the president of India. Famous Bengalis include poet and Nobel laureate Sir Rabindranath Tagore and filmmaker Satyajit Ray.