"Game of Thrones" has won more Emmy awards than any other television drama in history. When the eighth and final season begins tonight on HBO, some 30 million Americans are expected to tune in. Tens of millions more will be watching live in nearly 200 countries and territories around the world.

The show is based on a series of fantasy novels written by George R.R. Martin, but don't let the dragons and magic fool you, this is no kids show. The characters are complex, and the storylines full of graphic violence, sex, and shocking surprises. Whether you're a fan or not, we thought you'd be interested to learn the unlikely story of how "Game of Thrones" began, and how it turned into one of the most popular television series ever made.

"Game of Thrones" is set in the mythical seven kingdoms of Westeros , whose ruler historically sits on the Iron Throne

Feuding families, vie for power.

Manipulation and murder, tools of the trade.

A giant wall protects the seven kingdoms, winter has come, and with it, the threat of total annihilation from a seemingly unstoppable army of the dead.

Anderson Cooper: for you, what is the show about?

Emilia Clarke: Power.

Anderson Cooper: Power?

Emilia Clarke: What it does to someone, how much we covet it, how it goes wrong in the wrong hands. and how different it is when you have it versus when you're coveting it.

Emilia Clarke plays Daenerys Targaryen, also known as the mother of dragons. She leads armies, raised dragons, and has killed a lot of people in her quest to take the Iron Throne.

Anderson Cooper: Extraordinary the sheer number of ways that people are killed.

Emilia Clarke: Oh, it's incredible. We really kill 'em good. Daenerys is pretty old school with her burning.

Anderson Cooper: But I guess the dragons also can eat people?

Emilia Clarke: Indeed. But they like to char them before they-- (LAUGH) and so a burn is always involved in a dragon (LAUGH) they like their meat cooked. (LAUGH)

Actress Maisie Williams is Arya Stark, a teenager seeking revenge for the murder of her father.

Anderson Cooper: well, how many people have you killed?

Maisie Williams: Oh, gosh. I-- I've lost count. I think in the book, she has, like, the highest kill count.

Williams was 12 when "Game of Thrones" started, she's now 22. This was her first acting job.

Maisie Williams: I didn't even wanna be an (LAUGH) actor. I wanted to be a dancer. And then my second audition was for "Game of Thrones" and then it all just--

Anderson Cooper: There are actors all over the world right now listening to that, screaming.

George R.R. Martin is the novelist behind this murder and magic. In 1996, he published the first in his series of books called "A Song of Iice and Fire." For years, Hollywood pursued him, trying to turn his books into movies.

George R.R. Martin: their approach was inevitably to simplify. Well, okay, these books are too big. We have to cut it all down. I didn't want it simplified. So I said repeatedly the-- the sexiest word in Hollywood, "No."

Anderson Cooper: That's the sexiest word in Hollywood?

George R.R. Martin: But, no, I don't wanna do it. until David and Dan came along.

David and Dan are David Benioff and Dan Weiss. At the time, they were young screenwriters and novelists with no television experience, but they loved the massive scale of Martin's story.

Anderson Cooper: I mean, no disrespect you-- were-- relatively novice in-- in this realm of television.

Dave Benioff: Yeah. It's not disrespectful. It's a fact--

Dan Weiss: Yes. No.

Dave Benioff: I mean, we had never produced anything.

Anderson Cooper: You'd never produced anything?

Dan Weiss: What we thought we were facing was a real uphill battle of trying to explain to him why he should avoid all of these film offers and accept these two guys who'd never made a television show before in their lives.

Dave Benioff: And really, he just wanted to know if we knew the books.

They knew the books cold and convinced Martin that if HBO signed on, they would make an epic, cinematic television series that was true to his story.

George R.R. Martin: I knew that none of the conventional networks were ever gonna put this on, not without taking out all the sex and 97 percent of the violence and making it a kiddie show that was on at 8. I wasn't gonna let that happen.

HBO agreed, seeing it as a series about much more than just dragons and occasional magic.

George R.R. Martin: If you have a story that is about the human heart in conflict with itself, about these very basic human emotions, about love and ambition and greed for power it doesn't matter if there's a dragon in it or if it takes place on an alien planet, or if it takes place in Faulkner's Mississippi.

Anderson Cooper: Human stories are human stories.

George R.R. Martin: Human stories are human stories, the rest is just furniture.

That focus on the humanity of the characters is what appealed to Peter Dinklage. He plays Tyrion Lannister, an outcast member of the ruling family of Westeros.

Dinklage was the first actor to sign on, despite reservations about the fantasy genre.

Peter Dinklage: Dwarves in this genre always have pointy shoes and-- and big beards or they're relegated to either comic relief or angry warriors without romance or any human characteristics, really. And that just doesn't attract me as an actor. But this guy, Tyrion Lannister, has all of that and then some.

Dinklage recommended Lena Headey to play his sister, the cunning and ruthless Cersei Lannister.

By the way, she also happens to be in an incestuous relationship with her other brother Jaime, played by Nikolaj Coster-Waldau.

Nikolaj Coster-Waldau: I mean I read the script and I-- then I was like, "Who? What?" I couldn't remember half the characters and--

Anderson Cooper: It is confusing-

Nikolaj Coster-Waldau: They had weird names all of them, then you don't remember the names.

Lena Headey: I felt like that in the beginning too. I was like, "Who's gonna watch--"incestuous twins, dragons?" Like, you know, I mean, part of me thinks, "I-- I don't know." And then it shattered all of that.

"Game of Thrones" was shot in ten different countries, at dozens of locations, many in remote and desolate places. Hundreds of crew members worked behind the scenes, and in all more than twelve thousand extras were used. Attention to detail was critical. Major battle scenes sometimes took weeks to shoot and had to be carefully choreographed.

And then there are the dragons. The challenge was making them as life-like as possible, especially when actress Emilia Clarke was supposed to be riding on them. Those scenes start as cartoon-like animation, in a process called previsualization.

Emilia Clarke was then filmed riding what in early episodes was a pretty low tech contraption.

Anderson Cooper: you're riding on a hard green shell?

Emilia Clarke: Yeah—And then there was like a pole on either end. And it's essentially like the dudes on the railway who "eh eh."And I'm there, kinda trying to, like, yes, this is badass. And everyone's like, it doesn't look badass. You look like Harry Potter. You look like you're on a broomstick. and people are just kinda looking around, being like, it looks kinda weird.

It doesn't look weird however, when edited together with special effects.

Some of the most important sets, they actually built from the ground up like Castle Black, which is in a quarry outside Belfast. Actor Kit Harington, who plays one of the central characters, Jon Snow, showed us around.

Anderson Cooper: What is so interesting that they built-- I mean, that you feel like this is an actual castle that's been here for hundreds of years. It's not some sort of CGI creation.

Kit Harington: That was al-- always with "Thrones," what I felt was amazing is there was a level of detail that went beyond what the audience sees.

Jon snow was killed in Castle Black and then magically brought back to life. Other main characters weren't so lucky. Ned Stark, played by actor Sean Bean, appeared to be one of the most important characters in the beginning of the series, then he got his head chopped off before the end of season one.

Anderson Cooper: I could not believe you killed off Ned Stark.

George R.R. Martin: I have this reputation of being exceptionally bloodthirsty.

Anderson Cooper: In person, you don't seem very bloodthirsty.

George R.R. Martin: "Star Wars" kills more people than I do. I mean, right in the opening of "Star Wars," they unleash the Death Star against the planet Alderaan. And--

Anderson Cooper: Right. But you don't know who's-- living on Alderaan or--

George R.R. Martin: Exactly. Death should mean something. So I try to make you feel the deaths. I don't necessarily have more than any other people, but I try to make you feel them more.

After Ned Stark was killed, all the actors realized their characters could be next.

Peter Dinklage: We'd get all the, all the scripts in one package.

Anderson Cooper: All the scripts for that season.

Peter Dinklage: Yeah, I would always go to the end, the last page of the last script of-- of episode ten and go backwards.

Anderson Cooper: To see if you were alive?

Peter Dinklage: To see if I die. Yeah. you just wanted to go out in a heroic way at least. You don't wanna go out, like, off-screen, like, "Hey, did you hear about Tyrion?" (LAUGH) "Aw, what?" "He died." You don't wanna go out that way.

The level of brutality in "Game of Thrones" has been controversial, particularly scenes of sexual violence and degrading treatment of women. Actors Gwendoline Christie, Liam Cunningham and John Bradley say there's a reason for showing it all.

Anderson Cooper: You know, terrible things happen to some of the women on the show.

Gwendoline Christie: This story is loosely based on the War of the Roses. And I would say, learn. Learn that this is what has happened in history, and this is not what needs to happen in the future.

Liam Cunningham: This is a grownup show written by grownups for grownups. Violence is disgusting. We show kind of the reality of it.

John Bradley: The unpleasant, ugly nature of what human beings are capable of doing to other human beings.

Now that the final season is about to start, there are plans to shoot a prequel series, and HBO intends to turn Castle Black and other locations in Northern Ireland into tourist attractions. Props used in the show are still stored in a warehouse outside Belfast.

For a fan of the series, it's like visiting a shrine. There are stacks of dummy dead bodies from battles, dragon head skulls, and one of Kit Harington's most famous costumes, which weighs about 30 pounds.

Kit Harington: Hold it from that hanger.

Anderson Cooper: Gee-- (LAUGHTER) wha-- I can barely hold this thing.

Kit Harington: Yeah.

Anderson Cooper: Wow.

Remember Ned Stark, who lost his head in season one? We found it.

Kit Harington: We got Ned's head.

Anderson Cooper: That's Ned's head?

Kit Harington: That's Ned's head.

Anderson Cooper: Oh my God.

Perhaps the most iconic characters of all in "Game of Thrones," are White Walkers, supernatural villains who control an army of zombie-like followers called wights.

Much of their look was created at this studio in Kent, England, by Barrie Gower and his team.

Anderson Cooper: People say I look like a White Walker all the time. I get made fun of all the time.

Gower agreed to show us just how complex the makeup for White Walkers is.

Separate pieces of silicone are painstakingly applied with glue, then makeup and paint, fills in the details. The whole process takes about four hours. The transformation is startling.

Anderson Cooper: I keep forgetting that I'm dressed like a White Walker. You would think you would feel this. But it-it actually after a while, it just kind of feels like your regular skin.

Barrie Gower: I think the temperature of the pieces warm up to your body temperature. And I think it's quite easy to forget that you're wearing something. And it is like a second skin.

Despite all the meticulous attention to detail, and careful planning, about halfway through the series, the "Thrones" executive producers, Dan Weiss and David Benioff, realized they had a problem. The TV show was catching up to the end of George R.R. Martin's books. Martin had promised two more novels to end the story, but he'd missed all his deadlines.

He told the producers how he thought his books would end, but he didn't have all the details. So for the final seasons Weiss and Benioff, who produced the TV series from the beginning, were on their own to decide how the game ends.

Anderson Cooper: What is the feeling as a writer who's dreamed up all these characters, all of a sudden to see it taken in a direction that is not directly of your making?

George R.R. Martin: Dave and Dan have done the most popular TV show in the world. I gave my baby out for adaption and, and this is not my baby any more. But the books are still my baby.

At the end of last season Jon Snow and the mother of dragons united with some of the leading families in Westeros to try to stop the advancing army of the dead. But can humans put aside their differences to save themselves? Or will greed, and distrust, be the end of the seven kingdoms?

We can't tell you how it all ends, but this is how the final season begins.

Produced by John Hamlin. Associate producers, Kate Morris and Kara Vaccaro