[Kenji]

I'd wager that everyone back then who made a name for himself with intellectual pursuits was a polymath. Simply because knowledge was hard to come by and you couldn't specialise so much that you remained ignorant about the grand scheme of things of everything else, like it is possible today.

[azernik]

Or alternatively, the breadth of human knowledge was small enough that one person could hold most of it in their head.

[mordant]

One of my favorite party questions is, "Who was the last man who knew everything?"

[hutzlibu]

I doubt, that there ever was such a man.

For example knowing about plants and animals. We as whole humanity are still far from knowing them all on the earth, so how could somebody from history knew them all?

And even if you only count "everything" as the whole current knowledge of humanity, then also no, as there are for example tribes in the jungle who know about plants or hunting technics the genius in europe never heard of.

[a3n]

> I doubt, that there ever was such a man.

I've heard this question before. I think it's more useful to think of it as "When was the last era when it was possible for one person to know everything that's known?"

Doubtful that there ever was such a particular person, at least because of geography, as you point out, and different concerns in different parts of the world. But there must have been such an era; I don't know when that was.

[UweSchmidt]

Who do you have in mind? Maybe

https://en.wikipedia.org/wiki/Alexander_von_Humboldt