Gleichschaltung is a German word that is usually associated with the history of Nazi Germany. It means "coordination," "making the same", or "bringing into line," and refers to the process of establishing a totalitarian system.
But Nazi-ism was not the first totalitarian system nor was it by any means the most successful. That dubious honour belongs to the Christian religion. It is therefore appropriate to apply this term with all its connotations of totalitarianism, tyranny and forcible standardization of culture to the process by which Christianity took over the rich pagan world of Europe and transformed it over the centuries into the arid abstractionism of Christian totalitarianism.
Where it found a rich and varied religious topgraphy, it left a bleak, spiritual desert, much like the actual desert that spawned it.