Controlling figure succeeded; very English — The Greatest! (8)
I believe the answer is:
svengali
'controlling figure' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'succeeded very english the greatest' is the wordplay.
'succeeded' becomes 's' (genealogical abbreviation).
'very' becomes 'v' (abbreviation).
'english' becomes 'eng' (abbreviation).
'the greatest' becomes 'Ali' (Muhammad Ali was known as the Greatest).
's'+'v'+'eng'+'ali'='SVENGALI'
Can you help me to learn more?
(Other definitions for svengali that I've seen before include "Control freak" , "Master manipulator" , "Leavings of a fictional evil hypnotist" , "Manipulative person" , "Person who controls another's mind - musician and evil genius (created by George du Maurier)" .)