During this time, their leader, a philosopher named Landru, became deeply concerned that the wars raging on Beta III would destroy all life there. To solve the problem, he built an extremely sophisticated computer, also called Landru. Landru absorbed the members of Beta III's society, eventually exerting absolute control over the thoughts and feelings of the entire planetary population. Landru created "the Body", similar to a hive mind, which eliminated hate, fear, and conflict, put an end to war, disease, and crime. But Landru also eliminated the soul of the civilization, which reverted to a time comparable to Earth's late 19th century. Though policed by the Lawgivers, the people moved through their lives as an arrested culture – living in a blissful daze, nothing changed for almost six thousand years.
In 2167, the planet was visited by the Federation starship Archon. Many of the ship's crew, known to the Betans as the Archons, interacted with the Betans, however they were discovered by Landru, and the ship was forced down and destroyed there by Landru's heat beams. According to Reger, though the Archons attempted to resist Landru, many were killed in this endeavor, while others were ultimately absorbed into the Body.
A century later, in 2267, the USS Enterprise arrived at Beta III to investigate the disappearance of the Archon. The scouting party, consisting of Lieutenants Sulu and O'Neil, visited the planet, but were soon identified by the Lawgivers as being Archons because their clothes, which included bicornes, were incorrect. A followup landing party, consisting of Captain James T. Kirk, Commander Spock, Doctor Leonard McCoy, Lieutenant Lindstrom, Galloway, and Leslie, arrived on the surface. Soon after, they discovered the existence of an underground, and an incredible power source, determined to be Landru. After Kirk outmaneuvered Landru, disabling the machine, a team of sociologists, including Lindstrom, were left behind to give the culture a "more Human form." (TOS: "The Return of the Archons")
By the late 24th century, the Betans were considered by Starfleet to be a legacy civilization. Largely forgotten in the century that has passed, Landru somehow became operational again, reasserted itself and persuaded the Betans to return to worshiping it and resume red hour purging. In 2380, Captain Carol Freeman and Commander Jack Ransom of the USS Cerritos intervened and remind the Betans not to listen to Landru, and had spent a morning reiterating Captain Kirk's original message to the local population. Simultaneously, Ensigns Beckett Mariner and Brad Boimler beamed down to the planet to distribute art supplies to children to promote creative thought. (LD: "No Small Parts")
This species was identified by name in the episode "No Small Parts". In "The Return of the Archons", they were consistently described as being "Human". This fits with the comic book The Return of the Archons, Part 2, wherein Beta III was revealed to be a lost Federation colony.