In some places he also had to rely on his own estimates and criteria to keep the data reasonable and consistent:

With any historical data, accuracy is always a concern, and urban populations were rough and infrequent estimates up until the Industrial Revolution.īye has used a variety of data sources-including the UN and many research papers-to create the dataset used in the video. The World’s Largest City Throughout History

His video covers cities with a minimum population of 10,000 and hints at historical events which led to the establishment, growth, and eventual fall of cities. Mapper and history YouTuber Ollie Bye has visualized the seven largest cities in the world since 3,000 BCE. So maintaining large urban centers, and especially the world’s largest cities, was a monumental task. And their size requires a host of many other services-such as transport and sanitation-that are traditionally expensive to maintain. But that also means that cities usually consume more primary goods than they produce.

Global city in geography quiz world