Early Period: West Bengal once formed a part of a wider region of India called Bengal. In prehistoric times, Dravidian and other tribes lived in Bengal. They were small communities of hunter-gatherers and left behind a number of stone implements.
After about 1000 B.C., peoples from central Asia spread east and reached Bengal. They introduced the Sanskrit language, and knowledge of agriculture, weaving, and pottery.

In about 200 B.C., Bengal was part of the Maurya Empire, but it remained densely forested and sparsely populated. In about A.D. 300, the Guptas conquered Bengal. Trade with the Mediterranean, and particularly with Rome, expanded over the next 200 years. However, with the fall of the Roman Empire in the 400's, the economy declined. Several dynasties succeeded the Guptas. Sasanka, a ruler of the Gauda dynasty, tried to stem the rising tide of Buddhism in the region.

It was only with the founding of the Pala dynasty in 750 that Bengal became united once again. In the next 450 years, many cities emerged along the Ganges River. Bengal became a centre of Buddhism, and art and learning flourished.

Turkish invasions across northwest India brought Islam to Bengal at the beginning of the 1200's. Pathan kings, who came originally from Afghanistan, followed them. The most notable was Sher Shah Suri, who took advantage of the death of the first Mughal emperor, Babur, to extend his territory from Bihar into Bengal.
However, during the period 1575 to 1576, Akbar returned the region to Mughal rule. He wanted the rich resources of rice, silk, and saltpetre (the chemical used to make gunpowder).

European invasion. The increasing power of the Muslims drew the Portuguese toward the subcontinent. Before long, they faced competition for trade from the Dutch and the British. In 1632, the Emperor Shah Jahan attacked the Portuguese port in Bengal and reduced the merchant power of the Portuguese.

Meanwhile, the British strengthened their trading links with Bengal. In 1609, the British acquired three villages around which Calcutta later developed. They built a fort, known as Fort William, and thereby consolidated their position. In 1700, Bengal became an independent presidency under the jurisdiction of the British East India Company.

On the death of the emperor Aurangzeb in 1707, the Mughal territories in Bengal were absorbed into the independent kingdom. The British soon gained a monopoly over internal trade. The Company merchants abused their trade privileges, however, and thus came into conflict with the native ruler, the nawab of Bengal. The conflict came to a head at the Battle of Plassey (1757) in which the nawab was defeated. In 1764, the East India Company took over the right to collect the revenues of Bengal and virtually annexed the region for the British.

During the 1800's, Bengal became the economic and political centre of British India. Agricultural raw materials, such as indigo, opium, and later jute, became staples of trade. Engineering industries grew as Calcutta expanded into a major port and an important railway junction.
Bengal was enlarged by the addition in 1863 of the town and surrounding district of Darjeeling, bought by the British from the rajah of Sikkim in 1835. Religious movements such as the Brahmo Samaj grew out of the meeting of traditional Hinduism with Christian missionary activity in the 1830's. Bengal also became the major centre of cultural and political activity in modern India.

Partition and independence. Until 1905, Bengal included much of modern Bihar and Orissa, as well as the whole of Bengal. Lord Curzon's partition of Bengal in 1905 created two new states, East Bengal and Assam, and West Bengal, Bihar, and Orissa. The partition roused fierce political opposition among Bengalis, who played prominent roles in the national movement for independence.
It also encouraged the split between Muslims and Hindus which resulted in Bengali Muslim support for the creation of Pakistan and national partition in 1947. The division into the two new countries caused the migration of more than 5 million people and appalling massacres as Hindus and Muslims fled.