The Turei were a space-faring culture from the Delta Quadrant. In the late 24th century, they were the current keepers of the underspace corridors that traverse the Delta Quadrant. This underspace was once the property of the Vaadwaur, but in 1484 the Turei led an alliance of the Vaadwaur's enemies, launching a massive orbital assault on the Vaadwaur homeworld.