According to director Robert Eggers, his new star-studded revenge epic "The Northman" is a giant popcorn film and a historically accurate picture of Viking culture and mythology.

Alexander Skarsgard stars as Amleth, a Viking prince who flees to the North Atlantic after his uncle (Claes Bang) cruelly murders his father, King Aurvandil (Ethan Hawke).

Years later, disguised as an enslaved person, Amleth journeys to Iceland to avenge his father's murder and liberate his mother, Queen Gudrun (Nicole Kidman). He meets a fascinating woman named Olga (Anya Taylor-Joy), with whom he develops his first genuine human relationship since his youth.

"There really hasn't been an accurate Viking movie ever before, and I was working with the greatest historians and archaeologists in the field and, one thing is for sure, this is the most accurate Viking movie that's ever been made," Eggers told Reuters at the film's London premiere.

Skarsgard produces "The Northman," having spent several years developing a Viking epic before meeting Eggers.

"It's been a dream of mine since I was a little kid growing up in Sweden, surrounded by runestones," he explained.

Skarsgard, 45, underwent a physical change to play the hefty Viking, working with Magnus Lygdback, his "Tarzan" trainer.

"When Amleth transforms from his human state to his spirit animal, he becomes a hybrid of a bear and a wolf, so it was important to bulk up a bit and get a bit bigger," he explained.

Eggers, who previously directed two feature films, "The Lighthouse" and "The Witch." directed the film's brutal, large-scale action scenes for the first time. It required meticulous preparation and organization to keep track of his hundreds of extras, stunt performers, and animals.

"He adores authenticity, extended takes, and sequences without cuts. It's quite difficult to capture large-scale action set pieces with only one camera and one shot. As a result, we had to practice them numerous times and work on the choreography and the characters' relationship with the camera "Skarsgard spoke about the experience.

"The Northman," which also stars Icelandic singer Bjork in her first major motion picture appearance in 17 years, opens in theaters worldwide in April.