The city of Mumbai, formerly known as Bombay, first consisted of seven islands that were separated by swamps. These islands were first part of the Magadhan empire around a thousand years ago. They subsequently became a territory of the Sultan of Gujarat in 1343. When the Portuguese captured the islands in 1534, they named the area Bom Bahia, which means 'the good bay' in English (the English pronunciation was Bombay). Mumbai was established as a trading center by the Portuguese, and it grew due to the trade of products including silk, rice, cotton, and tobacco. In 1662, Mumbai was given to King Charles II of England as a wedding gift from his bride's father. The King did not want the burden of ruling Bombay, so he had the East India Company rent the islands instead. Under the East India Company, Governor Gerald Aungier changed the face of this port city. People were allowed to buy land and build their own houses under the notion that this was a city that was meant to be built under God's assistance. Also built were forts, a castle, a church, a hospital, and causeways linking the islands. As settlers arrived, the population grew to nearly 60,000 by 1675. The 1688 Mughal attack of Mumbai resulted in a large decrease in population size, as much of the city was destroyed. However, by the end of the 1700’s, Mumbai became known as “The Gateway to India” as it grew tremendously due to trade and employment opportunities. Jewelers, weavers, ironsmiths, planters, and servants came to be abundant. The swamps that separated city’s seven islands were filled in by 1845, creating a single island. Additional change occurred when the first Indian railway opened, which offered a new form of employment and attracted more citizens to the city. As time progressed, the East India Company created government buildings throughout the city. The population continued to increase, and by 1991 it was 9,900,000. In 1995, the city name was changed from Bombay to Mumbai, which is derived from Mumbadevi, the stone goddess of the ancient deep-sea fishermen of the islands.
Sources:
http://www.bl.uk/learning/histcitizen/trading/bombay/history.html