a) Charlemagne was the King of Franks and Roman Emperor. He was responsible for uniting western and central Europe. Clovis also united the Franks into a single kingdom. Charlemagne also was Christian and Clovis became Christian in 496.
b) Charlemagne was a weak military leader while Clovis was a strong one.
c) Because of Clovis’s strong military leadership, he achieved military dominance over other Germanic tribes, but Charlemagne mixed Germanic, Christian and Roman elements to have dominance, because of that Merovingian kings retained their titles and the kingdom was united due to oath. Clovis divided his kingdom between his sons and this was also a reason for his downfall.