After Aang and his friends brought the Hundred Year War to an end, the Avatar and Fire Lord Zuko transformed the Fire Nation colonies into the United Republic of Nations, a society where benders and nonbenders from all over the world would live together in peace and harmony, Republic City being its capital city. Avatar Aang accomplished many remarkable things in his life, but his time in this world came to an end, and thus the Avatar Cycle began anew.