Nearly 10 million people watch “House of the Dragon,” making it the most-watched HBO premiere ever.

HBO’s “House of the Dragon” had to live up to the high standards set by “Game of Thrones.” HBO’s biggest series premiere ever happened because fans of the high fantasy show were at least interested enough to watch the first episode.

Warner Bros. Discovery released data on Monday about how many people watched the first episode of the prequel series on linear TV and HBO Max on Sunday night. The number was 9.986 million. The production company says that this new original series has the largest audience in all of HBO’s history.

The company says that 20% to 40% of an HBO show’s total viewers usually watch on Sunday nights.

Casey Bloys, the chief content officer for HBO and HBO Max, thought it was great that so many “Game of Thrones” fans joined us in Westeros last night.

“House of the Dragon” tells the story of the Targaryen civil war, which happened about 200 years before the events in “Game of Thrones.” It is based on George R.R. Martin’s book “Fire and Blood.” This book in Martin’s “Song of Ice and Fire” series is different from the other books in the series because it has a narrator who knows everything and writes the history based on what other people say happened. There are different stories about what happened, and sometimes these stories are at odds with each other.

When “House of the Dragon” premiered on HBO and HBO Max, there was a lot at stake because the company’s new CEO, David Zaslav, is looking for ways to cut costs. Cost-cutting measures like laying off workers and getting rid of HBO Max content have become the norm at the recently merged company.

Warner Bros. Discovery is trying to save money by combining its streaming services, but this will cost money and take time.

“House of the Dragon,” the second book in the Game of Thrones series, has a lot to prove and keep up. Many “Game of Thrones” fans were unhappy with the last season because the writers went beyond what happened in the books by George R. R. Martin, who hasn’t finished the story in his books.

On Rotten Tomatoes, “House of the Dragon” had 413 reviews as of Monday afternoon and an 83% “Fresh” rating. For comparison, the first episode of “Game of Thrones” in 2011 got a 90% “Fresh” rating. In fact, every season except the last one got at least a 90% rating. 55% of people watched the eighth season.

Analysts, investors, and, most importantly, Warner Bros. Discovery executives will be keeping a close eye on “House of the Dragon’s” viewership numbers over the next few weeks to see if the show can keep going strong for the rest of its 10-episode season.