Siegfried poetically soldiers on after ring's brought back (7)
I believe the answer is:
sassoon
'siegfried' is the definition.
(I know that siegfried can be written as Sassoon)
'soldiers on after ring's brought back' is the wordplay.
'soldiers' becomes 'sas' (Special Air Service).
'after' says to put letters next to each other.
'ring's' becomes 'o's' (letter resembling a ring).
'brought back' is a reversal indicator.
'os' reversed gives 'so'.
'on' put after 'so' is 'soon'.
'sas'+'soon'='SASSOON'
'poetically' is the link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for sassoon that I've seen before include "Poet condemning war" , "Siegfried --, English poet and novelist" , "Siegfried ---, war poet" , "Siegfried --, poet and writer" , "Siegfried --, English writer" .)