Is martin luther king jr a martyr?

is martin luther king jr a martyr? did dying help his cause? would he have furthered his cause if he had not died? would he have been less effective if he had not been shot? and when he said "I may not get there with you. But I want you to know tonight, that we, as a people, will get to the promised land!" did he know he was going to die? did he let himself be shot because he knew it would happen, or was he unaware? it is quite mystifying and aerie at the same time.