Which was the first city to reach a population of one million people?

The first city known to man to reach a population of one million people was Rome, Italy in 133 B.C. London, England reached the mark in 1810 and New York City, USA made it in 1875. Regarding Beijing, China, it reached 1 million people in 1855.

In about 133 B.C. the city of Rome was the first to surpassed a population of one million because of its history, government (international relations), infrastructure, healthcare, and cultural demographics (compared to the world population of about 200–300 million at the time).

Today, we are told that there are over 300 cities in the world that have a population in excess of one million. Two of the current largest cities are now found in China. They are Chongqing and Shanghai. The first has a population of over 30,165,500 and the second has about 24,256,800 people within the city proper (its official administrative boundaries).