General Discussions

This officer was apparently leading the 1er chevau-legers-lanciers at Waterloo however Lieutenant-Colonel Guillaume-Felix du Dumanoir appears to have been in command it until a Prussian cannon ball took his head off. Can anyone give me more details of both issues i.e. Dumanoir or Dubessy leading the regiment, and also "a Prussian cannon-ball"? Why Prussian, were his regiment in action against Bluecher?