Slayor was a planet orbiting a star on the on the other side of the Orion Nebula from Earth. About AD 3240 Erasmus Chang was forced to land on it by a squadron of Zanat space ships while investigating the disappearance of four Loki Salvage Service scout ships.
It was an Earth-like world that the Zanat were in the process of conquering. The natives lacked hyperdrive and were at a black-powder and cannon stage of development making them easy prey to the Zanat. Never-the-less, the Slayors were still putting up resistance when Chang arrived.