Clovis, King of the Franks. This is another in the Biography from Ancient Civilizations series. Again, this is great content with nice visuals, but again it is a little dry like a giant encyclopedia entry. On the other hand, like the others in this series, it is divided into five chapters that are easy to in one day, so it lends itself well to being read over the course of a school week.
All said, have you ever tried to find a children's biography of Clovis? I think that this is it.