Huge engineering projects help spark intricate cities that transform the lives of millions of people. The spread of Christianity and other religions reveals the increasing interconnectedness of mankind. The greatest mega-city on earth, Rome, becomes an engine of expansion while China builds an empire on the other side of the world. A vast network of roads and shipping lanes allows goods and ideas to flow across three continents. Mankind is connected like never before—this is the birth of globalization.
Source: History Channel