Source: Exploring Eberron
There have always been gnoll clans in the Barrens, though the Dhakaani goblins ruthlessly exterminated gnolls in imperial territories, driving them back into the wilds. But their story starts long before. In the dawn of time, Eberron was the domain of the fiendish overlords. This was an age of chaos, as the overlords constantly clashed with one another. Rak Tulkesh, the Rage of War, commanded armies of fiends, while the Wild Heart raised hordes of ravenous beasts. In the struggles between the two, the Wild Heart bred dire hyenas with the ability to consume the immortal essences of the Zakya warriors of Rak Tulkhesh. But the Wild Heart failed to anticipate how consuming fiends would affect its creations. Twisted from within by the immortal essence of the demons they’d devoured, the hyenas were warped into something entirely new, something that was neither beast nor demon: and so the first gnolls were born.
Formed from both War and the Wild, gnolls were recruited and bred by both Rak Tulkhesh and the Wild Heart. As foot soldiers of the overlords, they fought against orcs and other early humanoids, as well as battling the gnoll clans of other overlords. Even after the overlords were defeated and bound by the Silver Flame, gnolls continued to be their pawns. The fiendish spark burned within them, and when they weren’t directly serving the Lords of Dust, most engaged in vicious acts of brutality. The Rage of War seeks endless battle, and when there is no greater conflict, it delights in setting its minions against one another. For countless generations, gnolls fought troll, ogre, and other gnolls seeking blood for their hungry idols.
Then, centuries ago, two gnolls from rival clans faced one another on a battlefield soaked in the blood of their kin—then questioned the path that had led them there. The two urged others to deny the voice that called for endless war, to refuse to chase death in the service of a fiend. Two became four, then eight, until entire clans heeded the call. Clan leaders dragged their idols to the place now known as Znir—a word that simply means “stone”—and there, they shattered the images of the fiends they once served. Together, the gathered hunters, shamans, and warriors swore an oath: They might be many clans, but from this day forward, they would be one pack. They would allow no one—not chib, god, or demon—to hold dominion over them.
This was easier said than done. Fighting the fiendish influence within was challenging enough, but the Barrens were a chaotic tapestry of battling forces. The leaders of the newly forged Znir Pact had no desire to rule over other creatures, but even just holding territory could invite attack. And so they developed the path that has carried them forward to this day: the road of the mercenary. The gnolls would claim no territory beyond the lands around Znir. They would fight for any who would pay a fair price. But if anyone sought to enslave a gnoll, or to strike against Znir itself, they would face the wrath of all of the united clans. This was a lesson that had to be taught many times, but after a century or so, the point was made. To those who paid them, the gnolls were as reliable as stone. Those who betrayed them or who picked a fight would fall before the might of the full Pact.
Some scholars of the Five Nations find it strange that the Znir Pact never took the path of conquest. There was no parallel to the united force of the Pact within the region, and they could have defeated the various chibs and warlords they served. But the gnolls have never had a desire to rule other creatures; they love the hunt and the thrill of battle. The path of the Pact allows them to do what comes naturally—to stalk and kill, to fight endless battles—but they do so together. They choose the paths they follow and the battles they fight. One could look at the Pact and say that they serve many masters. But the Znir gnoll would respond that they serve only themselves: that they choose who they fight for, they set the terms of their service.