ABSTRACT
The history of the world includes remarkable stories of migration in every era. Within the past fifty years, migration from countryside to city in every corner of the world caused the proportion of city-dwellers to expand from onefifth to over half the human population. Human life, previously rural, has now become dominantly urban. Urban areas of over twenty million inhabitants include Tokyo, Mexico City, New York, Bombay, Istanbul, São Paulo, and Jakarta: of these, only Tokyo and Istanbul had populations of as many as 100,000 inhabitants in 1800.
