Synonyms for Charles I (same or very similar meaning)
WordNet sense 1 (as Charles II he was Holy Roman Emperor and as Charles I he was king of France (823-877)):
Charles, Charles the Bald, Charles IIWordNet sense 2 (son of James I who was King of England and Scotland and Ireland; was deposed and executed by Oliver Cromwell (1600-1649)):
Charles StuartWordNet sense 3 (king of the Franks and Holy Roman Emperor; conqueror of the Lombards and Saxons (742-814)):
Charlemagne, Carolus, Charles the GreatFrom the ODE community, based on WordNetadd/edit