The Omega IV natives were a humanoid species who inhabited the Class M planet Omega IV. The planet was inhabited by two ethnic groups, the Yangs, a parallel to the Americans, and the Kohms, a parallel to the Asian Communists. The Yangs and Kohms decided to fight the bacteriological war that Earth avoided.
Ronald Tracey, captain of the USS Exeter, broke the Prime Directive and made First Contact with the inhabitants of Omega IV in 2268. The USS Enterprise arrived six months later to find the Exeter still in orbit. When the Enterprise landing party beamed down, they found a group of Kohms about to behead a Yang captive. Captain Tracey, now residing on the planet, explained that the Yangs were "savages, impossible, even to communicate with".
While in a jail cell with Cloud William, James T. Kirk and Spock learned that the Yangs were massing for an attack against the Kohms. The Yangs defeated the Kohms and took Kirk and Spock captive. The Yangs turned out to worship the American flag and the United States Constitution. Kirk, however, showed them the true meaning of their "holy words". Cloud William remarked that he could not understand what Kirk meant, but he would follow the words to the best of his ability. (TOS: "The Omega Glory")