Clovis (c. 466-511) was the man who united the Franks under a single king rather than a group of chieftains.
Clovis’s wife Clotilde was a Catholic and converted Clovis to Catholicism, even though the ruling elite of the Franks were ordinarily Arians. Catholics believe that Jesus Christ is equal to God the Father in divinity whereas Arians believed that Christ was divine but not equal to God. Clovis’s baptism into Catholicism meant that the inhabitants of Gaul would become Catholic and the decline of Arianism commenced.
Clovis was the son of Childeric I, who is considered the founder of the Merovingian dynasty, although it was Clovis who united Gaul.