The question that comes to my mind is what drives you / researchers to seek out this information? What is happening, in the modern world, that might send you solutioneering towards dark periods in history like this?
If it helps at all, it might be worth noting there have been times in relatively modern history when humans were driven to physical cannibalism, in Russia for example, in times of extreme poverty and famine, humans can be driven to cannibalism.
The most annoying thing about this is that it is unnecessary, it's something pushed by the beast associated with us that makes us impose it on others, to maximise the energy it gets. In the system when it was zero sum, it was necessary for the energy-slave-worker ants to annihilate one another at the periphery to preserve the energy in the heart, but now the system is no longer closed, the energy of the sun shines in through solar technology, but this is never monetised, when it should be monetised and distributed to all, not only to keep all alive, but to enable all to add value instead of being a load.
Its only when the energy being used is from the planet that we are a load. When the energy we use is from the sun we are no longer a load but something adding creatively.
This is where you should look, driven by your instinct to solutioneer, to what we can be, rather than what we were before, I think.
History doesn't really repeat itself, it's always moving forward.