other occurrences around that inflection point: https://en.wikipedia.org/wiki/History_of_the_Byzantine_Empire#Fourth_Crusade https://en.wikipedia.org/wiki/Hist

other occurrences around that inflection point: https://en.wikipedia.org/wiki/History_of_the_Byzantine_Empire#Fourth_Crusade https://en.wikipedia.org/wiki/History_of_the_Byzantine_Empir... https://en.wikipedia.org/wiki/Black_Death https://en.wikipedia.org/wiki/Black_Death