Fyodoi

The Fyodoi were the human settlers of the planet Fyodos. For a long time, they lived in peace with the native species of the planet, the Galidyn. Eventually, however, the Fyodoi began to war amongst one another, and their destructive technology caused widespread devastation, in a war called the Great Cleansing. The Galidyn fled the conflict, hiding in their underground cities, while the Fyodoi destroyed one another. After the war ended, the surviving humans abandoned the ruins of their once-great cities, and shunned all technology completely. They reverted a Stone Age level of society, and cut themselves off from the Galidyn, who they now regarded as technology-worshipping monsters.