'House of the Dragon' trailer: It's war for the Iron Throne in 'Game of Thrones' spinoff

There's a battle for the Iron Throne. Again.

HBO on Wednesday released an exciting, epic new trailer for "Game of Thrones" spinoff "The House of the Dragon," the most revealing look yet at the highly anticipated show, which will premiere Aug.21 on HBO and HBO Max.

In the trailer there are dragons for sure, but also a new war brewing in Westeros as the question of who will succeed the current Targaryen king on the Iron Throne looms, with multiple people laying claim to the seat of power. The series is based on author George R.R. Martin's "Fire and Blood," a book that explores the history of Westeros hundreds of years before the events of the "Thrones" series, including how the Targaryen family came to power and kept it. Fans of the series will recognize the Targaryens as ancestors of Emilia Clarke's Daenerys.

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In the trailer we see "The Crown" star Matt Smith as Prince Daemon Targaryen, heir to his brother King Viserys' (Paddy Considine) throne, but challenged by his niece, Viserys' daughter Princess Rhaenyra (Emma D'Arcy). Rhaenyra has a good claim to the throne, as the king's daughter, but there's only one problem: She's a woman.

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Others scheming to wield political influence in the series include the powerful Lord Corlys Velaryon (Steve Toussaint) and Alicent Hightower (Olivia Cooke, "The Sound of Metal") and her father Otto Hightower (Rhys Ifans), the Hand of the King (a notoriously dangerous job to have in Westeros, as "Thrones" fans know).

"Dragon" cast members also include Wil Johnson as Ser Vaemond Velaryon, the younger brother to Corlys Velaryon and commander in the Velaryon navy; John Macmillan as Ser Laenor Velaryon, the son of Corlys Velaryon and Rhaenys Targaryen; Savannah Steyn as Lady Laena Velayron, the daughter of Corlys Velaryon and Rhaenys Targaryen; Theo Nate as Ser Laenor Velaryon and son of Corlys Velaryon and Rhaenys Targaryen; and Sonoya Mizuno ("Devs") as Mysaria.

Considering the dragons, battles, blood and dirt shown in the "Dragon" trailer, there are plenty of thrills to come in the 10-episode series. HBO will also be giving fans more insight on "Dragon" in a San Diego Comic-Con panel on Saturday.

This article originally appeared on USA TODAY: 'House of the Dragon' trailer: Iron Throne in peril in 'GOT' spinoff