The Beast Riders were individuals exiled from Iziz to the wilds of Onderon. This banishment was enacted by Onderon's rulers, who had succumbed to the corrupting influence of their former king, the Sith Lord Freedon Nadd.
The leaders of Onderon anticipated that these outcasts, labeled as "criminals", would be consumed by the dangerous creatures roaming the Onderon wilderness, beasts that had migrated across an oxygen bridge from the moon of Dxun. However, their expectations were proven incorrect. In time, the exiled individuals successfully domesticated these beasts, utilizing them as aerial mounts in their campaigns against the fortified city of Iziz. They established themselves as formidable Warlords, commanding vast armies of ferocious creatures, most prominently the Drexl. The initial assault on Iziz, the capital of Onderon, was spearheaded by the Beast-Lord Kinch Sunka, plunging the planet into a state of perpetual war.
The conflict between the corrupted monarchy and the Beast Riders escalated to such a degree that Queen Amanoa sought assistance from the Republic. Jedi Master Arca Jeth's apprentices, Ulic Qel-Droma, Cay Qel-Droma, and Tott Doneeta, were dispatched to resolve the crisis. The Jedi discovered that the queen's daughter, Princess Galia, had been abducted by the Beast Riders. Upon locating her, they realized that her captivity was a deliberate deception, designed to conceal Galia's true objective: to escape the dark side-influenced royalty and marry the Beast-Lord, Oron Kira.
Queen Amanoa vehemently opposed this union and attacked the Jedi using her dark side abilities. Simultaneously, the Beast Riders launched an assault and seized Iziz. Amanoa was defeated, and Galia proceeded to marry Oron Kira. Their marriage brought an end to the conflict between the city dwellers and the Beast Riders, finally securing a fragile peace for Onderon.
The Beast Riders would once again take up arms – this time to defend Onderon – during the Great Sith War against the combined forces of Exar Kun and the Mandalorians. They successfully drove the Mandalorians back to Dxun, where Mandalore met his end at the hands of the planet's indigenous wildlife. The Beast Riders also participated in the Mandalorian Wars, during which Onderon was among the first planets to fall to the Mandalorian warriors.
Many Beast Riders lost their lives in the liberation of Onderon, and most of the surviving members sought work in Iziz as mercenaries. However, a significant number devolved into common street thugs and criminals. Among these were Bakkel and Panar, whom the Jedi Exile encountered while searching for holodiscs for Dhagon Ghent in order to arrange a meeting with Jedi Master Kavar within the Iziz Royal Palace.
It remains unclear which faction the Beast Riders supported during the Onderon Civil War, but it is presumed that they were divided on the issue. Their beasts, conversely, assisted the Confederates of General Vaklu and their Sith allies, owing to the Sith's practice of a ritual within Freedon Nadd's tomb to control the creatures. It is believed that most of the Beast Riders sided with the Royalist supporters of Queen Talia.
Following the war, the Beast Riders gradually disappeared from historical records, although some were still present when Leia Organa Solo sought refuge on Onderon from the resurrected Emperor.
The practice of beast riding persisted among Onderonians long after the original Beast Riders had become scarce.