"Don Carlos" is a historical figure famously associated with the Spanish monarchy during the 16th century. Synonymous with him are several terms that evoke his significance and impact on Spanish history. One such synonymous term could be "Prince Carlos", highlighting his royal heritage. Additionally, "Infante Carlos" refers to his title as an heir to the Spanish throne. Another synonym could be "Carlos, Prince of Asturias", emphasizing his role as the heir apparent to the Spanish crown. Furthermore, "Don Carlos of Spain" signifies his noble standing within the Spanish aristocracy. Overall, these synonyms capture different facets of Don Carlos' identity and his significance in Spanish history.