In Mahabharatha there is a reference to the King of Vanga as an ally of Kauravas in their war against Pandavas. Evidences hint the presence of a well–settled civilization and culture in Vanga during the advancement of the Aryans to the place. Bengal was under the Mauryan rule in the 3^rd Century BC. 4^th and 5^th century Bengal was under the Gupta dynasty. By about 7^th century AD it had its own independent kings and rulers, the Palas. They were very strong and expanded their territory to Bihar, Orissa and Assam.

There are evidences, which show that at the height of their reign, the state had very high diplomatic relations with the Indonesian king Sri. Vijaya. In the 11^th century, Bengal was ruled by the Senas. They ruled with the capital as Nadia and were driven out by the Mughal ruler of Delhi, Quitb ud Din and it remained under the Mughal rule till Aurangzeb, the last of the Mughal rulers. After the death of Aurangzeb Bengal became independent and came under the rule of the Muslim governors. The last independent ruler of Bengal, Siraj ud Daula was defeated by the Britishers in the Battle of Plassey in 1757.

For the next seven years the Britishers were in a sort of dual control with the successors of Siraj ud Daula, Mir Jaffar and Mir Kasim. In the battle of Buxar Britishers defeated Mir Kasim and took the complete administration of Bengal.

In 1905, Lord Carson divided Bengal in to two   provinces and the division evoked much political unrest in the country and the whole nation stood together against the partition. Peace restored when partition was revoked by the declaration of King George V in 1911 at the Royal Durbar in Delhi. The capital of the British Empire was shifted to Delhi from Calcutta. In the time of independence Bengal was partitioned between India and Pakistan. The east portion became East Pakistan and the west remained West Bengal, a state of India.

In 1950 the Princely state of Cooch Bihar was merged in to West Bengal and the former French enclave of Chandennagore was added in 1954. Some parts of Bihar were transferred to West Bengal under the State Reorganization Act of 1956.