The Nawab of Bengal (Bengali: বাংলার নবাব) was the hereditary ruler of Bengal Subah in Mughal India. The Nawab of a princely state or autonomous province is comparable to the European title of Grand Duke. 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 (Bengali: বাংলা, বিহার ও ওড়িশার নবাব). The Nawabs were based in Murshidabad which was centrally located within Bengal, Bihar, and Orissa. Their chief deputy was the Naib Nazim of Dhaka.