It isn't though, I have seen the original source of this claim and its bs. The author just picks and chooses when empires begin and end so that it fits their claim. I would concede the point if it were ever actually an average.

[–] LwL@lemmy.world 1 points 1 week ago

I mean yea that doesn't surprise me in the slightest honestly, even outside of the number itself being pretty meaningless in the first place it's very fuzzy what the actual dates are.

[–] daydrinkingchickadee@lemmy.ml -2 points 1 week ago (1 children)

It's not just Glubb. The Changing World Order by Ray Dalio also arrives at the 250 year number.

[–] daydrinkingchickadee@lemmy.ml -3 points 1 week ago

Cliodynamics and Structural-Demographic Theory suggests cycles of 200-300 years as well.