Possible Clues:

• As a rule it takes a concerto to make him tops
• Naked ruler of fable
• Theatre in capital brought back Mikado
• Largest type of penguin
• Pre-Rome (anag.)
• Theatre dipped into capital to mount The Mikado
• Colin Thubron's novel concerto
• Monarch set up theatre company in European capital
• Ruler and a sheet of paper required
• Ere one has a romp with him, he's got to the top