- Disambiguation: You may be looking for the new game, Tribes Universe.
The Tribes series takes place in the future. The series spans from the 33rd century to the 40th century. The game's backstory stars in 2471 with a scientist named Solomon Petresun. Petresun is the invetor of first "cybrid", a bio-cybernetic hybrid artificial intelligence named Prometheus or IT. Based on ITS design, thousands of cybrids are mass-produced as slaves for the mankind. By 2602, Prometheus grows wary of humankind and rallies all cybrids produced to slaughter the humans in an event known as The Fire. These events take place in Earthsiege, the precursor of the Tribes series. Several details have since been retconned.
In Starsiege continuity, the Terran resistance manages to drive Prometheus' initially victorious forces out of Earth and onto the Moon where they are consequentially decapitated by General Ambrose Gierling and his squad's suicide attack on the cybrid base in 2627. Prometheus nonetheless survives destruction. After achieving immortality Petresun deems himself the Emperor of Mankind in 2652. He unifies the Terran civilization. Petresun begins to exploit the Martian and Venusian colonies, which leads to massive protests among the colonists by 2802. Imperial Knight Harabec Weathers leads a Martian rebellion. These events take place in Starsiege.
Tribes: Vengeance begins the Tribes series. Imperial King Tiberius is now ruling the Great Human Empire. He has hunted down almost all the cybrids and has expanded into the Interstellar Transfer Conduit. Outcasts, also known as "the Children of Phoenix" or simply Tribals arise and are extremely restless. The Blood Eagles are forced into conflict with them, but they too eventually embrace the Tribal way in Tribes: Vengeance.
Starsiege: Tribes sees an increase in the conflict between the Blood Eagles, the Children of Phoenix, and other tribes. This leads to many battles and the Tribal Wars of 3940. Tribes 2 focuses on this insurgent rising of the Bioderms, a new hybrid of workers and warriors created by the Empire as a replacement for the cybrids. They begin to assault the Wilderzone. The Tribes: Aerial Assault does not add significantly to the game's universe.