He also united the Fire Islands into a single political unit and eventually became to be known as the first Fire Lord, The history of the Fire Nation from inception was documented extensively by the Fire Sages, who commissioned an ever-growing mural in the corridors of the Dragonbone Catacombs, which also served as the burial sites for all of the deceased Fire Lords.
Along with the murals, numerous scrolls detailing the recorded history, personal accounts, and myths of the Fire Nation were also placed along the corridors, pertaining specifically to certain subjects in the nation's past, such as the unification of the Fire Islands by the first Fire Lord and the origin of the Kemurikage.
The military of the Fire Nation was engaged in an imperialistic century long war with the other three nations from 0 to 100 AG, during which the country committed genocide of the Air Nomads, conquered vast swathes of the Earth Kingdom, and instituted raids that annihilated the waterbending population of the Southern Water Tribe, save for one bender.
The ruler directly after the conclusion of the Hundred Year War, Fire Lord Zuko, used Fire Nation resources to help rebuild the world, named after the grandfather of Zuko and Azula, Fire Lord Azulon.
The government also issued educational reforms to ensure that young citizens developed a strong sense of patriotism and were properly indoctrinated to the nation's political agendas.
For instance, historical textbooks were heavily censored or modified to justify the Fire Nation's war efforts and courses that provided opportunity for personal expression were removed from the curriculum as they were potential threats to the Fire Lord's unquestioned authority.
As a result, both spirituality and respect for life rapidly declined, leading to the near extinction of the dragons and the brutalization of the Agni Kai.
With the coming of Sozin's Comet that greatly enhanced firebending, Sozin launched his attack on the air temples in hopes of killing the next Avatar, Aang.
Before the foundation of the United Republic and the following global technological revolution, it was also the strongest and most advanced country in the world.
Even though the Air Nomads were completely annihilated, the Avatar could not be found and disappeared.
The Fire Nation moved on to the Earth Kingdom, conquering much of its northwestern territories.
These people eventually congregated to form the Fire Nation after the lion turtles renounced their roles as protectors of mankind.
At this point, the ancestors of the first Fire Nation citizens left the lion turtle cities in favor of establishing settlements in the western hemisphere along the equator.