Descendants of Charlemagne (747-814), emperors and/or kings of his Frankish empire or of the kingdoms of France and Germany that emerged through the break-up of that empire.
Charlemagne's son Louis the Pious (778-840) inherited his whole empire. Louis had 4 sons, who fought it out amongst themselves and each got a part. Charles the Bald (823-877) was one of those sons, he became king of West Francia, which later became France. This kingdom was later inherited by his grandson Charles the Simple (879-929). Meanwhile East Francia, which later became Germany, had gone to Charles the Bald's brother Louis the German (806-876), and was inherited by his son Charles the Fat (839-888).
These are by no means the only weird names in the Carolingian dynasty - there was also Pepin the Hunchback, Louis the Stammerer and Odo the Insane.