The Massassi, the warrior caste belonging to the Sith species, revered Yavin as their god. This deity was symbolized by the gas giant known as Yavin Prime, which dominated the sky above its fourth moon. The Sith warriors were filled with both dread and inspiration by the red god's all-encompassing presence in the heavens. When the Sith Lord Naga Sadow commanded the Massassi to construct monuments, they interpreted it as a chance to elevate themselves. The Massassi built the temples in a futile effort to attain the status of gods, aspiring to reach their divine figure. The sacred texts known as the Books of Massassi documented the stories of Yavin.

Around the year 5000 BBY, Naga Sadow, the Sith Lord, suffered defeat in a battle fought over Korriban. Fleeing with his remaining followers aboard a lone starship crewed by Massassi warriors, Sadow chose to live in self-imposed exile on the isolated Yavin 4, which is the fourth moon of the gas giant called Yavin Prime.
Those Massassi who accompanied Naga Sadow to Yavin 4 began to view Yavin Prime, the red orb that dominated the sky, as a male deity that inspired both fear and fascination time. The warriors felt small and afraid under Yavin's powerful presence in the sky above. Sadow's order for his Massassi slaves to prepare the ground and construct temples on Yavin 4 was seen as an opportunity to ascend to Yavin's heavenly realm and become gods themselves.
The Books of Massassi, a compilation of engraved tablets, chronicled the Massassi's religious experiences with Yavin. Millennia later, Jedi from Luke Skywalker's Praxeum discovered the Books within a collapsed subterranean chamber located in the jungle. In 16 ABY, Streen, a Jedi Master, translated the tablets, leading to the rediscovery of the Yavin legend.
The 1996 novel Before the Storm, penned by Michael P. Kube-McDowell, only briefly mentioned the red god Yavin.