Complex sentence: The Latin Church, being the largest of these with a membership far greater than all the others combined, arose in Western Europe and North Africa, an area once encompassed by the Roman Empire, throughout which Latin was widely understood and spoken.
Split into simpler sentences: The Latin Church is the largest of these, with a membership far greater than all the others combined. It arose in Western Europe and North Africa, an area once encompassed by the Roman Empire, throughout which Latin was widely understood and spoken.