Charles II of England did not have a brother.
After Charlemagne, the name Charles (Karol) became even the standard word for "king" in Slavic (Czech and Slovak krl, Polish krl; South Slavic kral , krlj ; Russian ), Baltic (Latvian karalis, Lithuanian karalius) and Hungarian (kirly)
 Karl Sverkersson was a king of Sweden in the 12th century, counted as "Charles VII" due to a genealogical fiction of the 17th century by Charles "IX", but actually the first king of Sweden with this name

