The following tale is told of Charles, and the origins of his name: in 686, Pippin II and his wife Plectrude were talking together in a room when they were intruded upon by a messenger, bringing news that the Mayor's mistress, Alpaida, had given birth to a son at Herstal.The messenger, fearful of arousing the wrath of Plectrude, decided not to announce the news directly. Instead, he said: "Long live the king, it is a carl" ‎('man')‎. Pippin, equally cautious of his wife, dismissed the messenger as follows: "A carl, is it? Then let him be called that." This was done, and, so legend claims, the child was named "Carl". Alpaida also bore Pippin another son, Childebrand.
‎(bron wikipedia)‎