The Spanish Inquisition occurred just after the Spanish evicted the Muslims after 800 years of Muslim domination.
After 800 years, you're bound to absorb some of the bad habits of your oppressors.
Too bad it never seems to work the other way. The bad apple always spoils the barrel; never does the barrel of good apples cure the bad.
HOWEVER, Christians worked through the aberration, though it took over two centuries for the major conflicts to subside.
Islam considers it normal, not an aberration, to use violence & intimidation.