The Nawab of Bengal () was the hereditary ruler of Bengal Subah in Mughal India. In the early 18th-century, the Nawab of Bengal was the de facto independent ruler of the three regions of Bengal, Bihar, and Orissa which constitute the modern-day sovereign country of Bangladesh and the Indian states of West Bengal, Bihar and Orissa. They are often referred to as the Nawab of Bengal, Bihar and Orissa (). The Nawabs were based in Murshidabad which was centrally located within Bengal, Bihar, and Odisha. Their chief, a former prime minister, became the first Nawab. The Nawabs continued to issue coins in the name of the Mughal Emperor, but for all practical purposes, the Nawabs governed as independent monarchs. Bengal continued to contribute the largest share of funds to the imperial treasury in Delhi. The Nawabs, backed by bankers such as the Jagat Seth, became the financial backbone of the Mughal court. During the 18th century, the Nawabs of Bengal were among the wealthiest rulers in the world. The Nawabs, especially under the rule of Alivardi Khan of 16 years, was heavily engaged in various wars against the Marathas. Towards the end, he turned his attention to rebuilding and restoring Bengal. The Nawabs of Bengal oversaw a period of proto-industrialization. The Bengal-Bihar-Orissa triangle was a major production center for cotton muslin cloth, silk cloth, shipbuilding, gunpowder, saltpetre, and metalworks. Factories were set up in Murshidabad, Dhaka, Patna, Sonargaon, Chittagong, Rajshahi, Cossimbazar, Balasore, Pipeli, and Hugli among other cities, towns, and ports. The region became a base for the British East India Company, the French East India Company, the Danish East India Company, the Austrian East India Company, the Ostend Company, and the Dutch East India Company. The British company eventually rivaled the authority of the Nawabs. In the aftermath of the siege of Calcutta in 1756, in which the Nawab's forces overran the main British base, the East India Company dispatched a fleet led by Robert Clive who defeated the last independent Nawab Siraj-ud-Daulah at the Battle of Plassey in 1757. Mir Jafar was installed as the puppet Nawab. His successor Mir Qasim attempted in vain to dislodge the British. The defeat of Nawab Mir Qasim of Bengal, Nawab Shuja-ud-Daula of Oudh, and Mughal Emperor Shah Alam II at the Battle of Buxar in 1764 paved the way for British expansion across India. The South Indian Kingdom of Mysore led