Mumbai (; also known as Bombay, the official name until 1995) is the capital city of the Indian state of Maharashtra. It is the most populous city in India with an estimated city proper population of 12.4 million as of 2011. Along with the neighbouring regions of the Mumbai Metropolitan Region, it is the second most populous metropolitan area in India, with a population of 21.3 million as of 2016. Mumbai lies on the Konkan coast on the west coast of India and has a deep natural harbour. In 2008, Mumbai was named an alpha world city. It is also the wealthiest city in India, and has the highest number of millionaires and billionaires among all cities in India. Mumbai is home to three UNESCO World Heritage Sites: the Elephanta Caves, Chhatrapati Shivaji Terminus, and the city's distinctive ensemble of Victorian and Art Deco buildings.
The seven islands that constitute Mumbai were originally home to communities of Koli people, who originated in Gujarat in prehistoric times. For centuries, the islands were under the control of successive indigenous empires before being ceded to the Portuguese Empire and subsequently to the East India Company when in 1661 Charles II of England married Catherine of Braganza and as part of her dowry Charles received the ports of Tangier and Seven Islands of Bombay. During the mid-18th century, Bombay was reshaped by the Hornby Vellard project, which undertook reclamation of the area between the seven islands from the sea. Along with construction of major roads and railways, the reclamation project, completed in 1845, transformed Bombay into a major seaport on the Arabian Sea. Bombay in the 19th century was characterised by economic and educational development. During the early 20th century it became a strong base for the Indian independence movement. Upon India's independence in 1947 the city was incorporated into Bombay State. In 1960, following the Samyukta Maharashtra Movement, a new state of Maharashtra was created with Bombay as the