Possible Clues:

• Supreme monarchs
• As a rule, there's a concerto for one of them
• Rulers in a temper, or so it seems
• Some moths and penguins
• Big wheels
• Poem errs horribly - suggesting whose new clothes?
• Pu Yi and Napoleon
• 'They're on top, as a rule (8)'
• Franz Josef I and Haile Selassie
• Rulers showing false remorse about source of propaganda