One emperor backed follower of another (5)
I believe the answer is:
rasta
'follower of another' is the definition.
I know nothing about this answer so I can't tell whether this works.
'one emperor backed' is the wordplay.
'one' becomes 'a' (a thing is one thing).
'emperor' becomes 'tsar' (I've seen this before).
'backed' says the letters should be written in reverse.
'a'+'tsar'='atsar'
'atsar' back-to-front is 'RASTA'.
Can you help me to learn more?
(Other definitions for rasta that I've seen before include "Follower of Rastafarianism" , "Bob Marley, for one" , "sectarian worshipper" , "Often a Jamaican" , "Dreadlocked devotee" .)