single word requests - What do you call a person who leads a charge?

RAINA (eagerly turning to him, as all her enthusiasm and her dream of glory rush back on her). Did you see the great cavalry charge? Oh, tell me about it. Describe it to me.
MAN. You never saw a cavalry charge, did you?
RAINA. How could I?
MAN. Ah, perhaps not—of course. Well, it's a funny sight. It's like slinging a handful of peas against a window pane: first one comes; then two or three close behind him; and then all the rest in a lump.
RAINA (her eyes dilating as she raises her clasped hands ecstatically). Yes, first One!—the bravest of the brave!
MAN (prosaically). Hm! you should see the poor devil pulling at his horse.
RAINA. Why should he pull at his horse?
MAN (impatient of so stupid a question). It's running away with him, of course: do you suppose the fellow wants to get there before the others and be killed? Then they all come. You can tell the young ones by their wildness and their slashing. The old ones come bunched up under the number one guard: they know that they are mere projectiles, and that it's no use trying to fight. The wounds are mostly broken knees, from the horses cannoning together.
RAINA. Ugh! But I don't believe the first man is a coward. I believe he is a hero!
                        — Bernard Shaw, Arms and the Man