Journey I had guarded by soldiers (4)
I believe the answer is:
ride
'journey' is the definition.
(ride is a kind of journey)
'i had guarded by soldiers' is the wordplay.
'i had' becomes 'id' (I'd).
'guarded by' indicates putting letters inside.
'soldiers' becomes 're' (Royal Engineers).
'id' inserted inside 're' is 'RIDE'.
(Other definitions for ride that I've seen before include "Travel, on horseback, say" , "Journey on horseback" , "Jaunt" , "Be transported" , "badger" .)