West Bengal is a state in India's eastern area, bordering the Bay of Bengal on its eastern border. In terms of population, it is the fourth-most populated state in India and the fourteenth-largest in terms of land area. It has more than 91 million people. It is also the eighth-most populated country subdivision in the world, with a land size of 88,752 km2 (34,267 sq mi) and a population of 1.2 billion people. In the Indian subcontinent, it is a part of the Bengal area, and it shares borders with Bangladesh in the east and Nepal and Bhutan in the north. As well as the Indian states of Odisha, Jharkhand, Bihar, Sikkim, and Assam, it has a border with Bhutan. Kolkata, the state capital, is India's third-largest metropolis and seventh-largest city by population. It is also the country's third-largest port city. West Bengal is comprised of the Darjeeling Himalayan hill area, the Ganges delta, the Rarh region, and the coastal Sundarbans, among other places. The Bengalis are the state's largest ethnic group, with Bengali Hindus being the bulk of the population.
There was a series of Indian dynasties in the region throughout its early history; there was internal fighting; and there was a struggle between Hinduism and Buddhism for supremacy. The ancient Bengali city of Janapadas was the location of many important Janapadas, and the oldest towns in the region date back to the Vedic period. Many ancient pan-Indian dynasties, including the Vangas, Mauryans, and Guptas, were based in the area, and the region still exists today. The fortress of Gaua served as the capital of the Gaua Kingdom, the Pala Empire, and the Sena Empire, among other kingdoms and empires in the region. Following the Ghurid invasions led by Bakhtiyar Khalji and the creation of the Delhi Sultanate, the Muslim religion expanded across the whole Bengal area. Islam was introduced via commerce with the Abbasid Caliphate. During the reign of the Bengal Sultanate, the area was a significant trading nation in the globe, and the region was often referred to as the "richest country to deal with" by European traders. When the Mughal Empire conquered it in 1576, it became part of it. While certain sections of the area were controlled by Hindu kingdoms and Baro-Bhuyan landlords at the same time, other parts of the region were temporarily conquered by the Suri Empire during this time period. As a result of the death of Emperor Aurangzeb in the early 1700s, the proto-industrialised Mughal Bengal was transformed into a semi-independent state under the control of the Nawabs of Bengal, and early indications of the first Industrial Revolution were seen. In 1757, the British East India Company won the Battle of Plassey and annexed the area to the Bengal Presidency, which was established in the aftermath of this victory.