Yellow Neck uprising

"earth"

- He stood in the center of an unnamed village deep in the interior of the Earth Kingdom, newly "liberated" by Xu Ping An and the Yellow Necks [...] the stench of rotting flesh soaked through his clothes and the cries of survivors haunted the wind.

The Yellow Neck uprising was a large-scale rebellion in the central Earth Kingdom in the late 4th century BG.

Prelude
Kuruk was carefree Avatar, who left the four nations to figure out their problems by themselves. Along with his early death at 33, this allowed corrupt and ruthless people to grow in power, and resulted in instability around the world. Furthermore, all usual methods employed to find the next Avatar failed, and chaos grew worse in the seven years after Kuruk's death.

History
The rebellion broke out in the deep interior of the Earth Kingdom, an area that was also affected by great numbers of outlaws known as daofei. Led by a certain Xu Ping An, the Yellow Necks devastated the land, killing great numbers of people. The Earth Kingdom Army opted to not defend some of the remote hinterland, allowing the insurgents to plunder it at will. An acquaintance of Avatar Kuruk, Jianzhu, once saw a settlement destroyed by the Yellow Necks. The horrible sight left a lasting impacted on him, contributing to his decision to conspire with the Air Nomad monk Kelsang and solve the Avatar succession crisis through unconventional means.

Novels

 * The Rise of Kyoshi