Carloman of Bavaria was the eldest grandson of what descendant of Charlemagne?
Louis the German Louis (also Ludwig or Lewis) "the German" (c. 802-876), also known as Louis II, was the first king of East Francia. Grandson of emperor Charlemagne and the third son of emperor of Francia, Louis the Pious and his first wife, Ermengarde of Hesbaye, he received the appellation "Germanicus" shortly after his death in recognition of the fact that the bulk of his kingdom was in the former Germania.
Judith of Flanders Judith of Flanders (or Judith of France) ( 843 – c. 870) was queen consort of Wessex and countess consort of Flanders. She was the eldest daughter of the West Frankish King and later Holy Roman Emperor Charles the Bald and his wife Ermentrude of Orléans. Through her marriages to two Kings of Wessex, Æthelwulf and Æthelbald, she was twice a queen. Her first two marriages were childless, but through her third marriage to Baldwin, she became the first Countess of Flanders and an ancestor of later Counts of Flanders. One of her sons by Baldwin married Ælfthryth, a daughter of Æthelbald's brother, Alfred the Great. She was also an ancestor of Matilda of Flanders, the consort of William the Conqueror, and thus of later monarchs of England.