The Galateans were a race of robots.
At one time the human race was dying of a plague. Their solution was to create bodies for themselves that would be resistant to the plague. Keltor Jacobs created the Galateans and the humans uploaded copies of their minds into them. They were placed on the Moon until their activation. A cure was discovered just three hours after their activation.
Years later, the humans and the Alan Turing-worshipping Galateans, known as the Children of Turing, began to see each other as threats. The Phantom Piper began to control the dreams of the Galateans from the Dreamspace, making them think they were in a war zone. He eventually controlled them while sleepwalking into attacking the humans so that a war would start between them. Alan freed them from the Piper's control when he broke down the mathematical code that made up the Piper by using Block Transfer Computation. (COMIC: The Phantom Piper)
In an alternate timeline, the Galateans had rebelled and began attacking the humans. Keltor was about to use an electromagnetic pulse to disable them, but before he could, he was killed by Chiyoko so she could assure her creation.
The result was a war between the humans and Galateans which lasted for thousands of years. The Galateans and humans both worshipped Chiyoko as a god. Near the end of the war, before the destruction of Earth, Chiyoko decided that the Galateans were superior and that the humans would have to "go away".