Lord Of The Rings actor Billy Boyd composes and performs swan song for The Hobbit trilogy

Move aside, Bilbo Baggins.

The Hobbit may be the film franchise's title, but the final instalment of the long-drawn trilogy based on JRR Tolkien's novel belongs to another little fella: Thorin Oakenshield.

Bilbo (Martin Freeman) is sidelined in this instalment, which opens here on Dec 18.

After all, what's a hobbit to do in an epic battle between dwarves, elves, men and orcs?

Much like the The Lord Of The Rings trilogy finale, 2003's The Return Of The King, where Aragorn (Viggo Mortensen) is restored as the rightful titular royal, The Hobbit: The Battle Of The Five Armies sees Richard Armitage's Thorin reclaiming the lost Dwarf Kingdom of Erebor and its legendary treasure from the evil dragon Smaug.

Is Armitage the new Mortensen?

Both gained mainstream fame through Peter Jackson's Middle-earth trilogies, and their heroic characters quickly became fan favourites.

Jackson himself had admitted that Armitage, who is English and is something of a Hugh Jackman lookalike, was cast because The Hobbit movies needed a heart-throb like Mortensen.

Mortensen's post-Middle-earth career flourished with David Cronenberg's Oscar-nominated films A History Of Violence (2005) and Eastern Promises (2007).

The 56-year-old US actor continued to dabble in gritty, independent flicks and went somewhat under the radar.

HIGH PROFILE

But it is not that likely that Armitage will fade in the same way, even though the time has come to bid Jackson's trilogies farewell.

For starters, Armitage, unlike Mortensen, was already a popular figure in his native country before joining Jackson and company, thanks to high-profile TV productions like North And South, Spooks, Robin Hood and Strike Back.

He was also Jackson's first choice to play Thorin. In contrast, Mortensen was a last-minute replacement, after original pick Stuart Townsend had a falling out with the director.

The Brit is also a trained professional and his acting ability was what impressed Jackson.

We have seen how Armitage developed Thorin's character in An Unexpected Journey (2012) and The Desolation Of Smaug (2013), and in The Battle Of The Five Armies, where Thorin succumbs to "dragon-sickness", a corrosive illness that leaves creatures unable to resist gold.

That meant Armitage had to dig deep to display a gamut of emotions including joy, paranoia, fear, despair, covetousness, loneliness, anger and redemption. This is particularly so in a pivotal scene where Thorin walks alone in the hallowed golden halls, slowly descending into madness.

Tough, but there is nothing the 43-year-old London Academy of Music and Dramatic Art graduate cannot handle, having worked in British film, television and stage plays for more than a decade.

It also helps that Armitage is a professed fanatic of Tolkien's Middle-earth books. He read The Hobbit when he was seven and went on to devour The Lord Of The Rings, The Silmarillion and The Book Of Lost Tales.

"I'm really grateful to be part of this journey," said Armitage at the London press conference of The Hobbit: The Battle Of The Five Armies last week.

"Thorin has such an interesting arc over three movies. When does one ever get the opportunity to play a single story over three pieces?"

Like Mortensen, Armitage also favours serious, dramatic roles.

He told Wall Street Journal that "light, trivial comedy does not appeal" to him, but he is open to playing villains, such as Sir Guy of Gisborne in the BBC's Robin Hood or the Nazi/Hydra henchman in Captain America: The First Avenger.

Armitage recently won rave reviews for his powerful portrayal of John Proctor in the Arthur Miller play The Crucible, which ended its run at The Old Vic Theatre in London in September. It did so well that it will be screened in cinemas in the UK and Ireland this month, and other locations worldwide in February.

He also received a Best Actor in a Play nomination for the 15th Annual WhatsOnStage Awards, to be announced next year. It is the only UK major theatre awards decided entirely by theatre-goers.

Who is one of his competitors?

Another Brit-turned-Hollywood-favourite Tom Hiddleston, for his work in Coriolanus.

Although Armitage has yet to attain the standing of his fellow The Battle Of The Five Armies Brit co-stars such as Freeman, Orlando Bloom (Legolas), Benedict Cumberbatch (Smaug) and Luke Evans (Bard the Bowman), this last Hobbit film will certainly move him higher up the rungs.

He had already started working on Hollywood productions after filming for The Hobbit wrapped up in 2012. One was the disaster flick Into The Storm, which was a moderate worldwide box-office hit released earlier this year.

He is in the midst of filming Sleepwalker, a psychological thriller where he takes on the lead role.

No doubt having The Hobbit on one's resume is influential.

And with his good looks and willingness to play the fame game - he recently joined Twitter to keep in touch with his fans (known as the Armitage Army) and post personal tidbits - cinema's dwarf king is sure to enjoy supersized returns.