Ozai was the ruler of the Fire Nation during the final years of the Hundred Year War, reigning as Fire Lord from 95 to 100 AG. He was the second son of Fire Lord Azulon and Ilah, the younger brother of Iroh, uncle of Lu Ten, husband to Ursa, the father of Prince Zuko and Princess Azula, and the paternal grandfather of Izumi. Ozai was a firebending master and, prior to the end of the war, was believed to be the most powerful firebender in the world. After Iroh's only son, Lu Ten, died, Ozai usurped his brother's birthright to the throne in a scheme that resulted in his father's death and Ursa's banishment. Ozai's rule saw a mass buildup of industry and significant technological advancements. Like his father and grandfather before him, Ozai sought to conquer the other nations and become the supreme ruler of the world. To do this, he planned to utilize Sozin's Comet to burn down the Earth Kingdom, renouncing the title of Fire Lord and declaring himself the Phoenix King, ruler of the world. Before his plans could come to fruition, he was defeated by Avatar Aang, who used energybending to remove his firebending abilities permanently. The war ended with his reign.