When Mumbai was still Bombay, it was a cluster of seven Koli islands.Muslim ruler Sultan Muhamed Begada captured the by Hindu inhabited islands.
The Portuguese Occupation of Mumbai
The Portuguese Vasco da Gama found the sea route to Bombay, and several attacks followed. In 1534 the Sultan of Gujarat gave in and handed the islands over to the Portuguese, but the islands turned out not to be of any use to them. When King Charles II married the Portuguese princess Catherine Braganza, the Portuguese decided to give the islands to him in 1661.Charles II took over the remaining islands a couple years later. The East India Company saw the potential of Bombay as trading port because of its strategic location, and took over the island.
Over the years Bombay became one of the biggest industrial cities in the world, with Gerard Aungier as the "Father of Bombay." He was the one who persuaded businessmen from all over India to come and settle in this central city and so it developed into a great commercial centre.
Why Bombay Changed into Mumbai
England ruled over Bombay until 1947, when India became independent.
In 1960 Bombay State became Maharashtra, with Bombay as its capitol. It took until 1995 before the name Bombay changed into Mumbai. When Shiv Sena, a Hindu nationalist party, won the elections, they decided to give the city a different name. Since the name Bombay was given to the city by King Charles II, the Shiv Sena party thought this was too English. The party changed the name into Mumbai, based on the name of the Hindu goddess Mumbadevi.