|Anij, a female Ba'ku|
|Sojef, a male Ba'ku|
|Pages from a Ba'ku book|
The Ba'ku people were a technologically advanced humanoid civilization. In the early 21st century, the race developed the means of building weapons of mass destruction and was on the brink of self-annihilation. A small, enlightened group of the Ba'ku people escaped the horror of their unknown homeworld and found an isolated planet.
This group of Ba'ku followed a simple way of life and prohibited themselves from using technology. At first they were unaware of the metaphasic radiation in the planet's rings, which caused their aging process to significantly decelerate, although it was later discovered and cherished.
The Ba'ku society consisted of strong bonds between each individual as there were only six hundred living in the village. Their simpler way of life eventually prompted some of the younger Ba'ku villagers – who wanted to explore the galaxy with offworlders – to rebel against their elders, and an attempt was made to take over the village. When they were unsuccessful, they were exiled and eventually became the Son'a people.
In 2375, first contact between the Ba'ku and the Federation was established during a failed cultural observation mission, when a monitoring post was discovered on the planet. Lieutenant Commander Data disabled the post's duck blind, revealing the operation and the observers. Data subsequently informed the Ba'ku that the Starfleet and Son'a observers were their enemies, and attacked the support vessel in orbit with a scout craft.
Captain Jean-Luc Picard of the USS Enterprise-E headed to the planet, intending to capture Data and resolve the situation. Although Data was repaired, the question of why he had malfunctioned led the Enterprise crew to discover a cloaked Federation holoship hidden near the village. It emerged that Son'a leader Ru'afo planned to collect the planet's rings and harness the power of the radiation. Starfleet admiral Matthew Dougherty was cooperating with the Son'a, intending to kidnap the Ba'ku and take them to another world.
Ru'afo and Dougherty's plans were stopped when Picard and his crew resolved to protect the Ba'ku and alert the Federation council to the full scale of their plans, believing that the moral crimes that would be committed against the Ba'ku were not worth the advances in medical technology that would be gained by harvesting the radiation. Having delayed the procedure by preventing the relocation of the Ba'ku, Picard, Data, and Worf were able to gain control of the holoship, transport the Son'a off Ru'afo's ship, and destroy the Son'a collector.
According to the Insurrection novelization, the ancestors of the Ba'ku called themselves the Ka'bu (and the pacifistic dissenters made a linguistic play on the name by reversing the consonants to call themselves the Ba'ku, which meant "the Peaceful"). The Ka'bu had traveled the galaxy in sophisticated space vessels; they had lived elegantly, in the pursuit of beauty, art, and physical perfection, relying on mechanization to do their labor for them, instead of sweating out in the fields in coarse homespun. But the artist class had separated from the warrior class, and squabbling began - that class separation caused their downfall, not the availability of weapons.