Brought up the artillery on the wrong side (6)
I believe the answer is:
raised
'brought up' is the definition.
('raise' can be a synonym of 'bring up')
'artillery on the wrong side' is the wordplay.
'artillery' becomes 'ra' (Royal Artillery).
'on' indicates putting letters inside.
'the wrong' is an anagram indicator.
'side' is an anagram of 'ised'.
'ra' placed inside 'ised' is 'RAISED'.
'the' is the link.
(Other definitions for raised that I've seen before include "Collected for a purpose" , "Uplifted" , "Reared" , "Brought up or collected for cause" , "Erected" .)