Some observations.
1. For 1500 years the maximum size of cities was capped at around 450,000 inhabitants.
2. China has always had a massive population advantage over the rest of the world – this advantage remains today. Although whether it is always an economic advantage can be questioned.
3. By 1900 you can see the emerging power of the US with three cities in the top 10.
4. Despite their empire having one tits up London continues to display a remarkable concentration of the population of England in a single city.
Source: Four Thousand Years of Urban Growth: An Historical Census by Tertius Chandler. 1987, St. David’s University Press.