```The adoption by Clovis of Catholicism (as opposed to the Arianism of most other Germanic tribes) led to widespread conversion among the Frankish peoples, to religious unification across what is now modern-day France, Belgium and Germany, and three centuries later to Charlemagne's alliance with the Bishop of Rome and in the middle of the 10th century under Otto I the Great to the consequent birth of the early Holy Roman Empire. ```
