Mumbai (mōōmbī´, mŏŏm´bī), formerly Bombay (bŏmbā´), city (1991 pop. 3,175,000), capital of Maharashtra state, W central India, occupying c.25 sq mi (65 sq km) on Mumbai (Bombay) and Salsette islands on the Arabian Sea coast. Mumbai Island was created in the 19th cent. by reclamation projects that combined seven basaltic islets and is now a peninsula of the larger Salsette Island to the north. Salsette Island itself is connected to the mainland by causeways and railroad embankments.
Mumbai has the only natural deepwater harbor in W India, and is a transportation hub and industrial center. Manufactures include automobiles, machinery, clothing, chemicals, pharmaceuticals, electronic equipment, and refined petroleum. It is home to India's largest banks and financial houses and is also the center of India's domestic film and entertainment industry, the largest in the world. Shipbuilding and fish processing are also important industries. Although it contains vast slums, Mumbai is also a city of great wealth; most of India's tax revenues come from Mumbai. There is an extensive system of hydroelectric stations, and nearby at Trombay is a nuclear reactor.
The Univ. of Mumbai (founded 1857), the Bhaba Atomic Research Centre, and the Indian Institute of Technology are among the educational, medical, scientific, and technical institutions in the city. The National Centre of Performing Arts and Jahangir Art Gallery are some of the many cultural attractions. The Victorian-style India Gate near the waterfront commemorates a 1911 visit by King George V. On Salsette Island are Buddhist caves, and the nearby small island of Elephanta is noted for its hewn-stone temples. Mumbai has many large suburbs, including Andheri, Thane, and Ulhasnagar, each with a population of more than 100,000, and the city itself has the largest community of Parsis in India. Along the city's Arabian Sea coast, a 3.5 mi (5.6 km) bridge, opened in 2009, connects Mumbai with its northern suburbs. A rail network also connects Mumbai with its suburbs, and a monorail began operations in 2014. Sanjay Gandhi National Park is nearby.
The area of the city was ceded (1534) to Portugal by the sultan of Gujarat. Mumbai, after it passed to Great Britain in 1661, was (as Bombay) the headquarters (1668–1858) of the East India Company in W India. During the American Civil War it expanded to meet the world demand for cotton and became a leading cotton-spinning and weaving center. Mumbai was the capital of the Bombay presidency and later Bombay prov., which became the state of Bombay. In 1960 the state was divided into Gujarat and Maharashtra states, and Mumbai became the capital of the latter.
The city was convulsed by anti-Muslim riots in 1993. In 1995 the city was officially renamed Mumbai (its name in the indigenous language, Marathi). Mumbai's prominence as India's financial capital has also made it a target for violence from criminal gangs and terrorists. In 1993 a Muslim gang, apparently in revenge for the 1993 riots, was the cause of some 250 deaths from bombings, and terrorists were suspected in the July, 2006, bomb attacks that killed some 200 people. In Nov., 2008, terrorists attacked several well-known sites in the city, killing more than 170 residents and foreigners; the attackers were Pakistanis who apparently had ties to militant groups.