Fire Lord Sozin was the ruler of the Fire Nation during the early years of the Avatar: The Last Airbender series. He is best known for initiating the Hundred Year War against the Earth Kingdom and other nations, aiming to expand the Fire Nation's power and influence. Sozin believed in the superiority of firebending and sought to spread its dominance across the world. Sozin was also the grandfather of Zuko and Azula, two prominent characters in the series. His legacy is marked by the devastating impact of his actions, which set the stage for the events that unfold throughout the story.