The peaceful hunting tribe of the planet Neural led by Tyree, whom Kirk reluctantly armed with flintlocks after the Klingons supplied firearms to their neighbours.
The Hill People are a tribe of hunters living with bows and simple tools in the uplands of Neural. Kirk lived among them thirteen years before the events of the episode, during his first planetary survey, and became a blood brother of Tyree, who later became their leader.
In A Private Little War, Kirk returns to find the neighbouring villagers attacking the Hill People with flintlock muskets. He and McCoy discover that a Klingon agent is supplying the weapons and improving them step by step. Tyree's wife Nona, a kahn-ut-tu woman skilled in herbs, cures Kirk of a mugato bite and urges her husband to seek stronger arms.
Nona steals a phaser and is killed by the villagers. Tyree gives up his refusal to fight, and Kirk orders flintlocks made for the Hill People so that neither side can prevail.