The earliest known sign of anti-bending activity began somewhere between 30-20 BSC. Ping Xiao had lead a revolt in the Earth Kingdom capital of Ba Sing Se, a massive community encompassing nearly all of the northeastern corner of the kingdom. Ping Xiao ultimately lead and trained his troops for battle beneath the city, a complex tunnel running through the sewers and eventually leading to a deep cavern could mostly only be surpassed by members of the anti-bending triad. Eventually, the group siezed attack on the city by ambush and urged Avatar Roku to increase the amount of guards within the city walls, whilst dealing with the upcoming Hundred Year War and quarrels with Fire Lord Sozin.
Roku was able to intercept all messages sent between members of the revolt and reduced the amount of available weaponry, such as swords and knives, in local shops. Shortly after, he delivered a speech to the city and ended conflicts between benders and non-benders by promising more security and relations. It is unknown what became of Ping Xiao after the conflict had ended; however, it is implied that he had died somewhere after 20 BSC at an unknown cause. There is no known official name for his group.