How to emphasize the fact that the second event is separated from the first one by a big time span?
The arguments that you are presenting are quite ridiculous. Look, you delve into the medieval history, find some faults with the rulers of those times and accuse them of not observing human rights.
Don't you realize that that was an absolutely different dispensation? Humans' minds were different. The common notions were absolutely different. The very common sense was different!
Just consider the time when this whole idea of human rights came about. Did it really come about before the Great Schism of 1054 or, rather, long, long after?
This "long, long after" is not idiomatic, is it? So, what would be the idiomatic way of expressing that thought?