Successor to Claudius (4)
I believe the answer is:
nero
'successor to claudius' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nero that I've seen before include "Emperor said to have fiddled as Rome burned" , "Emperor, 'burnt' Rome" , "Emperor (who fiddled while Rome burned?) d. AD68" , "Famous fiddler" , "Tyrannical Roman emperor" .)