SLJ… When you've become so well-known in your field that people refer to you just by your initials, the term 'needing no introduction' seems an understatement. And for Samuel L Jackson, it really is: he is the second highest-grossing actor of all time – with his films boasting a total US box office of $4.63bn.

The actor returns to cinema screens this month in his latest film The Legend of Tarzan (co-starring our cover star Alexander Skarsgård), in which he swaps SLJ for yet another new identity – George Washington Williams, a US Civil War veteran who travels to the Congo and embarks upon an adventure with the film's eponymous hero…

How much exposure did you have to Tarzan prior to becoming involved in the film? What are your earliest memories of it?

Being a kid, sitting home watching black and white television and seeing Johnny Weissmuller and Lex Barker swinging on vines in the jungle. And from my generation, I saw Tarzan on the movie screen. It was the Gordon Scott era, when we had the muscle-bound Tarzan. Then Jock Mahoney played him once, I think. And I read tons of comic books. So when the opportunity presented itself, I thought, 'Yeah!' It was a no-brainer. I'd swing on ropes in my neighbourhood, pretending and playing Tarzan.

Did you get to swing on any ropes in the making of the film?

I actually got to swing on Alex Skarsgård's back during a fun scene you'll see in the movie. It was hilarious. The studio should make a ride of it: 'Ride on Alexander Skarsgård's Back'…

Samuel L Jackson in Tarzan

In your early conversations with director David Yates about the project, what was it that drew you in? Was it playing George Washington Williams?

Well, we talked more about George Washington Williams, who he was, and how David wanted him to be presented. And also his thoughts on who I am – in terms of the African American community in America and in the rest of the world, and how I could represent this character with the weight and credibility that he very much deserves.

George Washington Williams was a man of so many, many talents and such bravery. As a 14-year-old kid, he went off and fought in the war between the States; and after doing that, he went off to fight in the Mexican-American War; and then came back and joined the US cavalry. He served his country in whatever way he was asked to serve it. And he went on to run for office, became a preacher, and politician, and do so many other things.

It was an opportunity to let people know that there was this man, historically, who actually went to the Congo and wrote a letter to King Leopold II about what he was doing to its people. In this very public correspondence, he was the first to address this great holocaust that actually occurred as a result of Belgium's expansion into Africa. So, hopefully, people will see this movie and dig out their phones – or, as we used to say, 'go to the library' – and Google George Washington Williams or King Leopold or King Leopold's Ghost, and find out what actually transpired in the Congo.

Did David welcome your collaboration in shaping the character?

Oh, very much so. David's very smart and fair, and I think all those years of working with those kids [on the Harry Potter films] taught him to talk to actors in a very succinct, plainspoken and gentle way. He never asks you to do anything that you don't want to do, but he has the kind of personality that makes you want to please him. And when you do, he'll come out from behind the monitor, skip over to you and say, "That was perfect!" He would actually be skipping! Oh my god, he's happy. And you want to see that, so you tend to bend your will to what David wants.

It's fascinating that the filmmakers are weaving in the reality behind the romantic tales that were emerging out of Africa at the time that Edgar Rice Burroughs was writing the Tarzan adventures…

Oh, yeah. I love the reality of what goes on inside a story. We're obviously telling a fictional story, but George Washington Williams did go to the Congo. He did discover what King Leopold was doing. And David deals with those elements in a very real, positive way – when we see the records and the names of all the slaves they captured, and touch on the severity of what actually happened.

In the film, your character goes on this incredible journey with Tarzan into the jungle, which is a totally alien environment for him. Can you tell us about working with Alexander Skarsgård and creating the camaraderie that develops between your characters?

It's a fun relationship. Tarzan doesn't want to like George, but once he realises his tenacity and his commitment and loyalty, he begins to understand him a bit better. George is considerably older than everybody in the film, and Tarzan, Kwete [played by Osy Ikhile] and the other tribesmen, they run everywhere. So I decided that George would always be trying to keep up, saying, "Don't worry about me. I'm right here behind you." But by the time I show up, they've already made a plan and are getting ready to go somewhere else. I'd be panting. And they'd just look at me and take off running again. But George keeps his determination up, and every time they think that they've lost him, he shows up again, so that kind of makes them look at him in another way.

I first met Alex as a little kid when I was doing Deep Blue Sea with his dad [Stellan Skarsgård]. He would always be in Stellan's dressing room playing on the computer. So when we saw each other again on this film, I was like, "Man, you grew up!" I used to talk to him when he was a kid playing videogames in his dad's trailer so it was kind of fun to see him become what he's become.

When the opportunity to be in Tarzan presented itself, I thought, ‘Yeah!’ It was a no-brainer…

What kind of Tarzan do you think Alexander makes?

Alex has an interesting stoicism and a classic silence – it's old-school Hollywood hero stuff. The strong, silent type. This Tarzan just does what it is he has to do. As Jane says to Christoph [Waltz]'s character, Rom: "You picked on the wrong guy." Yeah. And it's really great that she's not a shrinking violet at any point in this film. I mean, she's never terrified at any point. She's just constantly looking at Rom like, 'No, you're going to get it. You're going to get it from him. And you're going to get it from me. It's coming.'

Margot Robbie is definitely bringing a feistier, more modern Jane to the screen. Did you get to play any scenes together?

We did. We walked together in the veldt and then we spent time in Kuba Village and there's a scene where Tarzan tosses her to me and I catch her. We actually shared the same trainer, and he would run Margot all around the park. I did Pilates mostly and so did she, so I'd see her when I was coming to Pilates and she was going, or the other way around. We actually spent quite a lot of time together. And we laughed a lot together.

Samuel L Jackson in Tarzan

You've obviously worked with Christoph Waltz in the past. Did you get to spend any time with each other on this film?

Not really. I shot at him once – I think that's the closest I got to working with him. We didn't have any scenes together, so he'd be going to work with second unit or something and we would see each other in passing.

When we spoke with Christoph, he told us he wants to do a movie just the two of you…

That would be awesome! I love him so much. I just love being in a room with him, chatting. I'd do whatever we could do together. We had so much fun on Django Unchained; those few months were great.

What are your thoughts on how this film is putting a new twist on the Edgar Rice Burroughs classic? Is this Tarzan a more three-dimensional character than we've seen?

People talk about the fact that Tarzan was raised by apes, and we've heard it, but this time you actually get a glimpse into what his journey was with the apes. We learn what his relationship was like with the ape who becomes his surrogate mother, and how the group felt about him. Many girl apes might have thought, 'Wow, he's so cute.' And then the boy apes are standing around saying, 'Why you like the hairless one? Look at me. But they picked on him. They beat him. They did stuff to him whenever they could. And we see how Jane met Tarzan – how she saw him for the first time and he saw her, and what that meant in terms of their dynamics.

He's in a country full of all these black people and apes, and, all of a sudden, there's this little white girl. He thinks, 'She kind of looks like me. I've seen myself in a reflection in a river,' and his mom did have a mirror. Jane identifies as African, and we see what that means to her. She takes him to the village and he learns who the tribesmen are and how they survive in this country that is so harsh, and the kindness and understanding of community and family they find there. So, we get to explore who these people really are in this film.

Was there a moment during production that was fun or memorable, or a scene that stands out as a favourite?

There are certain scenes that have a gravity to them that I understood when we were doing them, but until you see the film, you don't really get it. There's this moment when I'm sitting with Alex, after Tarzan has fought the gorilla and we're putting ants on him. We were talking about my life as a warrior and what it meant, and then the elephants come. I mean, we were just standing in an empty room when we did that scene, so when you're watching it and you see the elephants come it's pretty amazing.

It's incredible that visual effects have become so photorealistic that they no longer have to use wild animals in movies.

Yeah. They're no longer messing with animal's lives or changing their behaviour.

We were talking about my life as a warrior and what it meant – and then the elephants come...

How do you think the African backdrop contributes to the overall experience of the film?

Oh, it's definitely a presence in the film. In the light moments, when we're out walking in the veldt and the scene with Alex and the lions when we get to the village; or the waterfall sequence in the canyon with Djimon [Hounsou, as Chief Mbonga] and all of his warriors in the mist, with the light coming through the vines – all of those things are meaningful. It's how you convey, tonally, that we're in this place where something so mundane can all of a sudden become very, very dangerous indeed.

You've done Star Wars; you've done The Avengers; now you've done Tarzan

And I did King Kong, right?

You're just checking off your bucket list…

Yeah, man!

The Legend of Tarzan is in cinemas from 6 July. For more on the movie, read our interview with the king of the jungle himself, Alexander Skarsgård.