Relentless campaign (7)
I believe the answer is:
crusade
(Other definitions for crusade that I've seen before include "Religious war" , "Vigorous campaign" , "Holy war" , "Drive" , "religious campaign" .)
I believe the answer is:
crusade
(Other definitions for crusade that I've seen before include "Religious war" , "Vigorous campaign" , "Holy war" , "Drive" , "religious campaign" .)