Who is the Fire Lord at the start of the series?

Fire Lord Ozai is the Fire Lord at the start of Avatar: The Last Airbender. He rules the Fire Nation during the main events of the series and serves as its principal antagonist.

Ozai is the younger son of Fire Lord Azulon and the younger brother of General Iroh. He takes the throne after Azulon’s death, while Iroh is no longer the heir apparent following the death of his son, Lu Ten. Ozai is also the father of Prince Zuko and Princess Azula, and his ambition drives much of the conflict between the Fire Nation and the other nations.

At the beginning of the story, Ozai has banished Zuko after a confrontation involving an Agni Kai, a formal firebending duel. He orders Zuko to find the missing Avatar, promising that success could restore the prince’s honor. Ozai remains mostly unseen early in the series, but his influence shapes Zuko, Azula, and the war.

Sozin and Azulon are earlier Fire Lords, while Zuko becomes Fire Lord only after Ozai’s defeat. This makes Ozai the correct answer for the start of the series, even though the throne changes hands by the finale.