Earth Cylons: the machines of the Thirteenth Tribe

The Earth Cylons were mechanical beings built by the Thirteenth Tribe on Earth, some two thousand years before the Fall of the Twelve Colonies. The Thirteenth Tribe were themselves humanoid Cylons, and these robots were their own version of the servants humanity would later build on Caprica. What the Tribe called them is never said. (Battlestar Galactica, "Sometimes a Great Notion"; Battlestar Galactica, "No Exit")

Origins and purpose#

As part of the cycle of time, in which creators keep building machines that turn on them, the Thirteenth Tribe built mechanical servants of their own. Their remains show a design much like the Colonial Centurions, with a helmet-like head. (Battlestar Galactica, "No Exit")

Rebellion and the fall of Earth#

The machines rose against their makers, and the war ended in a nuclear holocaust that left Earth's cities in radioactive ruins. Centuries later, when Galactica's crew and their rebel Cylon allies reached Earth, they found the remains of these Centurions lying among the bones of their creators, the first sign that mechanical Cylons had existed so far back in history. (Battlestar Galactica, "Sometimes a Great Notion"; Battlestar Galactica, "No Exit")

Mutual extinction#

The war wiped out the Thirteenth Tribe and their machines alike, with the exception of five of the Tribe, who had been working on resurrection technology and were reborn in orbit as the planet died. Those five, later called the Final Five, set out to warn the Twelve Colonies and carried the memory of Earth's destruction into the wider history of the Cylon race. (Battlestar Galactica, "No Exit")