WW1 & 2 were just minor "cullings". The Black Plague (~1350 AD) was likely a cabal instigated "Mass Extinction Event" where approximately 1/3-1/2 of all Europeans were exterminated, and 60-70% of all men in some locations. Very likely caused by contaminated water and sabotaged sewage/sanitation. Whatever the cabal used it appears to have been targeting men in some locations (bacteria along with other stuff, probably cholera caused most deaths).

It looks like there was a "Mass Extinction Event" in the 1400-1500 AD timeframe that may have wiped out 50-80% of humans. Real history has been intentionally jumbled so unknown if this event was also the Black Plague+follow up events, and they have shifted the history timeline a bit.

There appears to have been another "Mass Extinction Event" that occurred near the end of the Roman Empire instigated by lead contamination from the lead water pipes (neruotoxins make people go batshit destructive and possibly sterilizes).

I suspect one in Ancient History around the Pompeii time frame. Unknown if they had ability to initiate volcanic eruptions at that time as is suspected now (directed energy). Santorini (Mediterranean) destroying itself was supposedly around 1500 BC, and this looks like another "Mass Extinction Event" to me (I don't believe the dates, but I believe the volcanic ash in the atmosphere can actually reduce crop yields and create starvation-induced depopulation and an excuse to blame "disease").

So this may be the 4th or 5th time. I regard "Mass Extinction" as at least 50% of the population. Historically, these events are identified by periods where there are suddenly a massive number of orphans or average age of population suddenly drops (as the young are most resilient with strongest immune systems).