Emperor in fine robes (4)
I believe the answer is:
nero
'emperor' is the definition.
(Roman emperor)
'in fine robes' is the wordplay.
'in' says the answer is hidden in the clue.
'NERO' is hidden in the letters of 'fine robes'.
(Other definitions for nero that I've seen before include "Emperor said to have fiddled as Rome burned" , "Roman emperor on the fiddle?" , "Roman tyrant" , "Emperor who played the fiddle" , "Matricidal emperor" .)