Scourge of God (6)
I believe the answer is:
attila
'scourge of god' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for attila that I've seen before include "He attacked the Romans" , "Devastating ruler" , "King of the Huns, d. 453" , "Well-known Hun" , "Warrior" .)