By Amy Longsdorf

As the regal warrior Aragorn, Viggo Mortensen finally fulfills his destiny and ascends the throne of Gondor in ”The Lord of the Rings: The Return of the King.”

In real life, Mortensen is finding his destiny, as well, as a Hollywood A-lister. But being a star is about the fartherest thing from his mind.

”I only start to think about work when I run out of money,” he says quietly. ”Whatever I’m looking at when I need to pay the rent, that’s what I do. Then every once in a while you get lucky. Every once in a while you get a phone call about a movie in New Zealand.”

Ah, New Zealand. Mortensen has grown so found of the country where he and his fellow Middle-Earthlings spent 15 months filming the ”Lord of the Rings” trilogy that he’d rather rhapsodize about the Land Down Under than talk about himself and his career.

Not for nothing is this guy nicknamed ”No Ego Viggo” by his castmates. In person, Mortensen is unassuming. When he arrives for an interview at a Beverly Hills hotel, he’s carrying a backpack, a steaming cup of Starbucks and a big silver pipe filled with greenish tobacco.

He is wearing a Fruit-of-the-Loom tweed shirt carefully tucked into his brown Wrangler cords. His hair is a few inches shy of a buzz-cut.

True to form, Mortensen points out that ”The Return of the King” is, like ”The Fellowship of the King” and ”The Two Towers,” an ensemble movie. But there’s no denying that in this grand finale, Mortensen’s Aragorn is king.

Aided by his buddies Gimli (John Rhys-Davies ) and Legolas (Orlando Bloom), Aragorn awakens the Army of the Dead and joins forces with the Riders of Rohan against the forces of Isengard.

Meanwhile, in another part of the forest, Frodo (Elijah Wood) and his traveling companions Sam (Sean Astin) and the duplicitous Gollum (voiced by Andy Serkis) continue on their journey to destroy the ring. Only when the bauble is hurled into the Cracks of Doom can it be annihilated.

Based on the book by J.R.R. Tolkien, ”The Return of the King,” opening Wednesday, is the third and final chapter in a series that has netted 17 Academy Award nominations and six Oscars. ”Fellowship” earned $860 million globally, while ”Two Towers” raked in $919 million. ”Return,” the longest of the movies at 3 hours and 20 minutes, is an epic in itself.

In ”The Return of the King,” Mortensen assumes the mantle of leading man. With his long hair whipping in the wind, brandishing a sword forged by elves, Aragorn saves the world.

Leave it to Mortensen to illuminate Aragorn’s weaknesses along with his strengths.

”Aragorn is very unquestioning in his willingness to sacrifice himself for the common good, but nevertheless he’s afraid many times in the story,” notes the actor. ”It’s how he deals with his fear, and overcomes his personal reservations in order to do what’s right for Middle Earth — that’s what we can learn from.”

In many ways, Mortensen and his fellow cast members have become their own private fellowship. They vacation together, and visit each other on movie sets. Many credit Mortensen with imbuing the production with his one-for-all, all-for-one spirit.

”Viggo leads by example,” notes Dominic Monaghan, who plays the hobbit Merry. ”He was so physically good at everything he did, he raised the bar for all of us. He’s also unassuming and quiet, yet very commanding. He brims with dignity.”

Ironically, Mortensen was a last-minute addition to the cast of ”The Fellowship of the Ring.” Director Peter Jackson was three days into shooting when he realized that Stuart Townsend wasn’t working out as Aragorn. Jackson made a phone call to Mortensen, who was wary of the long commitment.

The deciding factor for Mortensen was his then 11-year-old son Henry’s comments that the trilogy was ”too cool” to pass up. Mortensen repaid Henry, whose mother is the actor’s ex-wife, punk rock legend Exene Cervenka, with getting him a role in ”Return of the King” as an Orc.

Jackson recalls Mortensen’s first day on the set. ”He arrived in New Zealand and had 24 hours to get over his jet lag before he had to shoot the Weather Top scene where he defends the Hobbits. It was one of the bravest things that I’ve ever seen any actor do.”

Not unlike Aragorn, who seems equally at home with humans, Elves, Dwarves, Wizards and Hobbits, Mortensen considers himself a citizen of the world.

Born in Manhattan to a Danish father and an American mother, Mortensen moved with his family as a boy to Venezuela, Argentina and Denmark. When his parents split up, the actor, his two brothers and mother moved to upstate New York.

Before becoming involved in the Tolkien trilogy, Mortensen was best known for his supporting roles in diverse movies. He made his film debut as an Amish farmer in Peter Weir’s ”Witness” before playing a gas-station cowboy in ”Leatherface: The Texas Chainsaw Massacre” and a troubled Vietnam vet in Sean Penn’s ”Indian Runner.”

Next, Mortensen landed a showy role as Demi Moore’s uncompromising sergeant in ”G.I. Jane.” He was the con-man artist who romanced Gwyneth Paltrow in ”A Perfect Murder” and the bohemian blouse salesman who swept Diane Lane off her feet in ”A Walk on the Moon.”

Up next for Mortensen is ”Hildago,” the $80 million real-life story of Frank T. Hopkins, a cowboy and dispatch rider who competes in a 3,000 mile race across the Arabian Desert. The film is due in March.

At 45, Mortensen has suddenly become a sex symbol, although he tries to downplay the buzz.

”Doesn’t the sex symbol business happen to anybody in a popular movie?” muses the actor, who’s single since his split from Lola Schnabel, 23, the daughter of painter Julian Schnabel.

An avid poet, photographer and painter, Mortensen recently started a small company called Perceval Press to publish artwork by himself and others.

Director Peter Jackson says Mortensen’s artistic ambitions are very much in keeping with his determination to live in the moment and create art out of everyday experiences.

Ian McKellen, who plays the Wizard Gandalf, was surprised at Mortensen’s degree of dedication. ”He was very protective of Aragorn. He slept in his costume and kept his sword in the back of his car on days when he wasn’t filming. It was quite remarkable, really.”

With ”The Lord of the Rings” at its end, Mortensen is unwilling to let Aragorn go.

”You hear a lot of actors saying, ‘Oh, I can’t wait to get rid of that character.’ Well, we’re all going to forget things. We’re all going to lose our memories. That’s just what happens in life, right?

”So why be in such a hurry to forget, especially if you’ve learned something valuable.”