Handiest resolute knight sent to the front (7)
I believe the answer is:
nearest
'handiest' is the definition.
(near can mean conveniently nearby)
I don't understand the remainder of the clue.
(Other definitions for nearest that I've seen before include "Most local" , "Most imminent - most mean" , "Closest, being earnest" , "Most approximate" , "Stingiest" .)