Before the beginning of the Hundred Year War, Fire Lord Sozin occupied Earth Kingdom territories and transferred Fire Nation citizens to the area. When Avatar Roku confronted him about it, Sozin attacked, but Roku defeated him. However, despite his defeat, the Avatar never disbanded the colonies, and these first colonies would continue to thrive until 0 AG. As the Hundred Year War began, more land was occupied by the Fire Nation and more colonies were formed. These practices continued through the reign of Fire Lord Ozai, over 130 years after the occupation of Yu Dao.