Denethor II is the Steward of Gondor before Aragorn’s return.
Denethor II governs Gondor during the events of The Lord of the Rings. He is the twenty-sixth and last Ruling Steward, following a line of Stewards who administered the kingdom after its kings disappeared. His sons are Boromir and Faramir, and his seat of power is the White Tower in Minas Tirith.
Denethor is an intelligent and powerful leader, but his use of a palantír allows him to see some of Sauron’s strength without understanding the full situation. The experience deepens his despair when Mordor attacks. His grief over Boromir and fear for Gondor contribute to his final collapse.
A common mix-up identifies Boromir or Faramir as Steward because both are Denethor’s sons and important Gondorian leaders. Aragorn is the returning heir to the throne, not a Steward. Denethor’s title is therefore central to the political conflict in the story.