Succeeded, supporting independent soldiers (8)
I believe the answer is:
privates
'soldiers' is the definition.
(I've seen this before)
'succeeded supporting independent' is the wordplay.
'succeeded' becomes 's' (genealogical abbreviation).
'supporting' means one lot of letters go next to another (in a down clue, some letters go below others).
'independent' becomes 'private'.
's' after 'private' is 'PRIVATES'.
(Other definitions for privates that I've seen before include "It would be unseemly to expose these" , "soldiers" .)