HBO
It's one of the highest-rated cable shows, its twists causes the Internet to go crazy, and its viewers sell out fan events in minutes.
Yet, in order to find out what helped the series become a phenomenon, we have to go back to season 2's climatic "Blackwater" episode.
"Blackwater" not only brought "Thrones" to the masses, but was one of the most costly episodes ever produced for television.
Here's how the epic $8 million episode came together.
Preparing For Battle
According to series creators Dave Benioff and Dan "D.B." Weiss, preparation for the Battle of Blackwater episode started all the way back in season one.
"This whole story of Blackwater goes back to the first season ... we were supposed to have that battle with Tyrion and we ended up not able to shoot it," Benioff told EW. "We always promised ourselves, we're gonna have our major battle."
That major battle would turn out to be season 2's penultimate episode, "Blackwater." However, bringing a key conflict to life would be a serious production and financial challenge. Luckily, they were able to go to the source for help.
"Dave and Dan gave me the hardest episode of the season," author of the series and writer of the episode, George R.R. Martin told GQ. "I think it was their subtle revenge for creating such a difficult-to-produce show."
Hardest episode is an understatement. In the second book, "A Clash of Kings," the Battle of Blackwater is a war by land and sea that blows up a fleet of ships and takes up six chapters, so putting it together would undoubtedly be a challenge.
However, not as much as getting HBO to pay for it.
"You Guys Need A Million Dollars?"
According to E! Online, an average episode of "Game of Thrones" costs $6 million, making it one of the most expensive series on television.
However, "Blackwater" is not your average episode, so the creators told GQ they went to HBO to ask for more money:
Jamie McCarthy / Getty Images
Benioff: "We had one really intense conference call with the HBO brass. It was awkward: They said, 'So, what are you guys talking about, an extra $500,000?' We said, 'Noooo....' 'You guys need a million dollars?' 'Ummmm....'
Weiss: "I think we asked for $2.5 million. We got $2 million-something. That's a lot of money in TV."
In comparison, the average cable episode costs $2 million, so the extra costs for "Blackwater" alone equaled the price of one episode.
Where the Money Went
Typically, the show's large budget includes filming on location in places like Northern Ireland and Coatia.
For the "Battle of Blackwater" episode, the large budget went toward a three-part fight sequence that consisted of a large naval battle, beach fight, and castle storming.
Filming for the scene took place in Belfast where Benioff said they shot for about a month each night.
According to a season 2 featurette, the budget was spread across building ships, visual effects, and more than 250 extras that needed costumes and fight training.
A full-sized battleship based on those from the 14th century was constructed that included a large deck above and below ground.
They also built a castle battlement that guards overlooked while enemies approached on the attack.
Custom set props filled in for weapons.
Cast members, including Peter Dinklage, said they never had to pretend with the amount of detail put into the set.
In addition, the crew built a giant 4-foot deep water tank for stuntmen who were set on fire.
An impressive amount of visual effects were used to create a fleet of ships, their explosive destruction, and to add hundreds of more extras in battle.
This scene below of roughly 100 horses started out as just 13.
Benioff told EW the scene used more effects than any other episode done up until that point.
"We try to avoid excessive VFX on the show, but with 'Blackwater' there was no alternative," Benioff told EW. "[Visual effects team members] Steve [Kullback] and Rainer [Gombos] look over a large team of tech wizards and what they've accomplished is, in our completely unbiased opinion, some of the best effects work in television history."
All of it would go into making "Blackwater," but would the price tag be worth it for HBO and "Game of Thrones"?
A Fire And Blood Phenomenon
In short, "Blackwater" blew away both critics and fans.
Reviews of the episode were so positively received some called it the show's best episode "filled with as much spectacle as any episode of TV."
It would also become one of the series' highest rated episodes, pulling in 3.38 million viewers.
This would lead to a greater interest in the series, as ratings haven't gone down since.
By the end of season 3 the "Game of Thrones'" audience would nearly double to 5.39 million viewers. Not to mention, the millions more watching through HBO's online streaming service, HBO GO.
Yet, even though "Blackwater" would go on to help make "Game of Thrones" one of the most popular shows on television, the greatest battle may be yet to come, according to the creators.
"There's another battle bigger than this one coming up, but not until the end of season four," Benioff told GQ. "So we're preparing our speeches for how we're gonna ask for more money."