Although some early Sanskrit literature mentions the name Vanga, the region's early history is obscure. The eastern part came to be known be as East Pakistan , the eastern wing of newly born Pakistan and the western part came to be known as West Bengal, which continued as an Indian state. Despite the Trinamool Congress government's efforts to forge a consensus on the name change resolution, the Indian National Congress , the Left Front , and the Bharatiya Janata Party opposed the resolution.
Stone Age tools dating back 20, years have been excavated in the state, showing human occupation 8, years earlier than scholars had earlier thought. It was one of the four main kingdoms of India at the time of the lives of Mahavira , founder of Jainism , and Gautama Buddha , founder of Buddhism. It consisted of several janapadas , or kingdoms. Shashanka murdered Rajyavardhana, the Buddhist king of Thanesar, and is noted for destroying the Bodhi tree at Bodhgaya , and replacing Buddha statues with Shiva lingams.
It was followed by a shorter reign of the Hindu Sena dynasty. Subsequent Muslim conquests helped spread Islam throughout the region. The Bengal Sultanate was interrupted for a period of twenty years by a Hindu uprising under Raja Ganesha. Administration by governors appointed by the court of the Mughal Empire gave way to semi-independence under the Nawabs of Murshidabad , who nominally respected the sovereignty of the Mughals in Delhi. The company gained the right to collect revenue in Bengal subah province in with the signing of the treaty between the East India company and the Mughal emperor following the Battle of Buxar in The Bengal famine of claimed millions of lives due to tax policies enacted by the British company.
The Indian National Army was subsequently routed by the British. The western part went to the Dominion of India and was named West Bengal , while the eastern part went to the Dominion of Pakistan as a province called East Bengal later renamed East Pakistan in The latter became the independent nation of Bangladesh in Both West and East Bengal experienced large influxes of refugees during and after partition in Refugee resettlement and related issues continued to play a significant role in the politics and socio-economic condition of the state.
During the s and s, severe power shortages, strikes, and a violent Naxalite movement damaged much of the state's infrastructure, leading to a period of economic stagnation. The Bangladesh Liberation War of resulted in the influx of millions of refugees to West Bengal, causing significant strains on its infrastructure. West Bengal politics underwent a major change when the Left Front won the assembly election, defeating the incumbent Indian National Congress. This was aided by the advent of information technology and IT-enabled services.
Starting in the mids, armed activists conducted minor terrorist attacks in some parts of the state   while clashes with the administration took place at several controversial locations over the issue of industrial land acquisition,   which became a decisive reason behind the defeat of the ruling Left Front government in the assembly election. Geography of West Bengal and Climate of West Bengal Many areas remain flooded during the heavy rains brought by a monsoon.
West Bengal is on the eastern bottleneck of India, stretching from the Himalayas in the north to the Bay of Bengal in the south. The Rarh region intervenes between the Ganges delta in the east and the western plateau and high lands. A small coastal region is in the extreme south, while the Sundarbans mangrove forests form a geographical landmark at the Ganges delta.
The Farakka barrage over the Ganges feeds the Hooghly branch of the river by a feeder canal, and its water flow management has been a source of lingering dispute between India and Bangladesh. The western plateau region has rivers such as the Damodar , Ajay , and Kangsabati. The Ganges delta and the Sundarbans area have numerous rivers and creeks. Pollution of the Ganges from indiscriminate waste dumped into the river is a major problem.
At least nine districts in the state suffer from arsenic contamination of groundwater , and as of , an estimated 1. The main seasons are summer, the rainy season, a short autumn, and winter. In early summer, brief squalls and thunderstorms known as Kalbaisakhi, or Nor'westers, often occur. Monsoons bring rain to the whole state from June to September. During the arrival of the monsoons, low pressure in the Bay of Bengal region often leads to the formation of storms in the coastal areas. The Darjeeling Himalayan Hill region experiences a harsh winter, with occasional snowfall.