Seventy-five percent perished due to tribal/clan rooted political genocide during a civil war that led to Spanish Guinea's independence from Spain.

The indigenous Bubi of Bioko Island have since co-existed with non-indigenous Krio Fernandinos; and members of the Fang ethnic group, who have immigrated in large numbers from Río Muni.

The Bubi people, both living in Equatorial Guinea and exiled abroad, have long held little political power and economic stake in their native land.

Indigenous Bubi folklore indicate that the tribe immigrated to Bioko Island some 3,000 years ago as a means of escaping servitude.

One perspective offers that the Bubi were once enslaved by a single continental African tribe,[3] likely another Bantu ethnic group that once occupied areas along the shores of West Africa.

[4] Another suggests those who immigrated to Bioko 3,000 years ago descended from enslaved members from a number of ethnic groups that existed up and down the West-Central African region during that time.

The Bubi were known to have had long battles against one another on an individual, family, district, city, and tribal level—this led to a near constant state of warfare on the island.

The Bubi were isolated and undisturbed for much time, leading them to form a unique society, language and belief system different from the mainland Bantus.

A German Gold Coast merchant wrote "The island of Fernando Po is inhabited by a savage and cruel sort of people," and that Europeans did not dare to dock upon their beaches, for fear of surprise attacks from natives with dart-weapons.

Surprise attacks on explorers and colonists were a common phenomenon during this period—in fact, the Bubi had a system of social rank that depended largely on how many rivals a man had killed through stealth or subterfuge.

[8] Nguema's regime was characterized by its abandonment of all government functions except internal security, which was accomplished by terror; he acted as chief judge and sentenced thousands to death.

[12][13] In 1998, many Bubi people were tortured to extract confessions following their arrest after launching several attacks on military barracks in which three soldiers and several civilians were killed.

[14] Bubi women were publicly humiliated in the courtyard of the police station in Malabo with some being forced to swim naked in the mud in front of other detainees whilst others were sexually abused.

In the ancient belief system of the Bubi, the head god was called Rupe (or Eri in the southern region of the island) who created and cared for the world.