@Godyssey@mythologymonday
Some ancient Greeks and Chinese not only knew the Earth was a "sphere", and some made reasonable estimates of the size.
Watching the Moon gave a clue. So Ancient Babylonians might have guessed first.
Most people in the last 10,000 years didn't consider the issue. The "Flat Earth" idea was invented by Victorians alleging the Church believed in it, to poke fun at religion.