[manoDev]

Doesn't the fall of the Roman Empire explain it?

At its peak it was a huge unified empire, it should be expected a lot of commerce and knowledge would move freely within its borders. The (slow) fall of the Roman Empire would be like watching the end of civilisation, a dystopian fiction of the survivor-apocalyptic kind.

The following centuries, all the way to our modern age, rulers tried to claim the title of Cæsar (Kaiser, Czar, ...), tried to claim a continuity of the empire (e.g. Nazi's III Reich) or even invoked past roman imagery (the roman eagle ["aquila"] is also present as a symbol of power in the USA [american eagle], in Russia [romanov coat of arms], in Germany [both the nazi's eagle and the bundestag's eagle]).

It's as if the world is still trying to "get over" the end of the Roman Empire.

[xg15]

Yes, that's the "root cause" - but from what I understand, the fall of the roman empire was not a singular event but rather some gradual development. Which is why it seems to be so difficult to define a specific point in time at which the middle ages began [1][2]

I wonder if one could define e.g. an "elephant horizon" - some point in time where, before, how an elephant looks was common knowledge (among the educated) and after which the knowledge was lost or replaced by myths so we got depictions like in the OP.

[1] https://en.m.wikipedia.org/wiki/Late_antiquity

> Precise boundaries for the period are a continuing matter of debate, but Brown proposes a period between the 3rd and 8th centuries AD.

[2] https://de.m.wikipedia.org/wiki/Ende_der_Antike (German only unfortunately)

[dragonwriter]

> even invoked past roman imagery (the roman eagle ["aquila"] is also present as a symbol of power in the USA

Perhaps even more clearly than the adoption of the American bald eagle echoing the Roman eagle is the bronze fasces in the House rostrum, a direct replication of the Roman symbol of authority from which, also, Italian fascism derives its name.