Sozin was the ruler of the Fire Nation from 58 BG until his death in 20 AG, and the instigator of the Hundred Year War. He was the son of Fire Lord Taiso and Lady Hazei, the brother of Princess Zeisan, the grandfather of Iroh and Ozai, and the great-grandfather of Lu Ten, Zuko, and Azula. He was succeeded as Fire Lord by his son Azulon. As the Fire Nation's Crown Prince, Sozin developed ambitions to reform and strengthen his home country, only to be repeatedly frustrated by existing power structures.[9] After Sozin ascended the throne, he became a revolutionary monarch by expanding the Fire Nation's industry, sponsoring new research and technology, improving internal security, initiating anti-poverty programmes, and modernizing both the government as well as the military. Conversely, his early reign also became marked by a rise of xenophobia, imperialism, militarism, and a decline of spirituality, with Sozin actively encouraging or outright kickstarting these developments.[10][11][12] In his early life, Sozin was also best friends with Avatar Roku, but their friendship became strained after Sozin immersed himself in the role of Fire Lord and Roku became a fully realized Avatar. Seeing the great progress and wealth of his state, Sozin desired the Fire Nation to encompass the entire world, a plan to which Roku was strongly opposed. Following a confrontation over this which ended in Sozin's defeat, neither spoke to the other until they were seventy years old. Upon meeting the Avatar again, Sozin left his old friend to die, and began a war that would last one hundred years.[1] Using the fire-enhancing power of a comet, Sozin eradicated the Air Nomads in an attempt to preemptively eliminate the next Avatar. His plan failed however, and he spent the last years of his life hunting the new Avatar, Aang, in vain.[1] Sozin continued to implement great reforms until his death, though his later policies were largely aimed at an increase of military strength, propaganda, and oppression of minority groups.[13][14]