First Countries to Reach 5 Million People

Ancient population figures vary wildly and are extremely hard to pin down. Primary sources almost always exaggerate, sometimes by orders of magnitude, making ancient demography a very inexact science.

And they're enjoying it.

Whatever. I was trying to be generous in my definition of national continuity. I am usually more stingy on this subject. If you want to discount the UK/England, too, that's fine with me.

Seeing as the borders of present-day Britain encompass a significantly larger area than England did in 1600, I think it's fair. Then again, even today 84% of Brits live in England, so the date by which Britain as a whole passed five million inhabitants will not have been too much earlier than the date at which England passed five million.

The arrival of Europeans and more importantly their diseases did some major damage to the total population numbers, but their plentiful food sources and domestication of various crops and animals could sustain a very large number of people.

Peru and Mexico were respectively at the southern and northern ends of the 'Empire Belt' of the pre-Columbian Americas. The Aztecs and culturally related states, the Maya, the Muisca and the Inca were responsible for the bulk of the Americas' population before European colonisation, at which point their population density started to count against their ability to fight off Old World diseases brought over by Europeans. The importance of those areas would remain though; it's not without reason that Spain's original two viceroyalties in the Americas had their capitals at Mexico City (ruling over North and Central America) and Lima (ruling over South America).

Wow... you've really launched to some big conclusions & harsh judgements there mate, and with zero evidence. If you look at the dates for the quiz, it has nothing to do with the socio-economic conditions of modern countries. I would have assumed Capistrano's surprise would have been due to how long Ethiopia has been settled by humans, and the empires there in antiquity and the middle-ages.