Western civilization in ancient times was a very different thing than it came to be in medieval times. In ancient times, the main thing that tied Western civilization together was Rome. Rome created one culture that it spread across its entire empire. To speak of Western civilization at this time was to speak of Roman civilization. By medieval times, this had changed in an important way. Now, the main thing that held Western civilization together was the Christian Church. The Church was the only thing that was common to all of Western Europe since it was politically divided and had no language in common. This meant that medieval Western civilization was tied together more loosely than Western civilization had been during the Roman Empire.