Projected Population in 2015: 21.9 million
Population in 2005: 18.2 million

The city's previous name, Bombay, was discarded as a relic of colonialism. But Mumbai itself is very much a relic of the colonial era. The land it occupies was ceded to Portugal by an Indian potentate in 1534, and then passed to Great Britain in 1661. Under British rule, Bombay developed into a major metropolis. Today, vibrant Mumbai is India's commercial and entertainment capital.