Among all the mighty war leaders assembled on the plains of Erebor and along the slopes of the Misty Mountains, the greatest general has to be film- maker Peter Jackson himself. The New Zealander marshals five enormous armies who clash amid an ear-splitting steel crescendo.
"Every battle scene is a challenge and how these latest scenes stack up against The Lord Of The Rings battles, I guess people will make their own decisions about that," he says.
"But, to be honest, this battle was probably easier than The Lord Of The Rings' battles."
These include the famous sieges at Helm's Deep in The Two Towers (2002) and at Minas Tirith in The Return Of The King (2003).
"In those days, we couldn't do as much with computers," Jackson explains, "so we had hundreds and hundreds of extras in hot costumes with people fainting and being carried off set.
"Now, with CGI, you can control the battles more and I can film them myself. I can be on a virtual set with a camera and be the cinematographer within the virtual scenes."
The major battle sequence that gives the last Hobbit movie its name rages throughout the film's final act and it brings together squadrons of orcs (with a few goblins and trolls in tow) who cross swords with troops of dwarves, elves, men and the giant eagles who fill the skies and shake the ground around the town of Dale, along the slopes of Erebor and as far as the dwarf outpost of Ravenhill.
"The battle is the climax of three movies' worth of storylines, which all continue to play out even as armies are clashing on the field," Jackson says.
Indeed, the director notes, if the audience is not invested in the characters engaged in battle, the huge CGI sequences lose their lustre.
"If you don't care about those fighting the battles, you are in trouble," he says.
"Story is about character. They drive stories and when we were editing the battle scenes, we realised if we went more than a couple of scenes without seeing one of the principal characters, the battle becomes a bit boring.
"Battles are just battles, with lots of sword- clanging, and that becomes boring pretty quickly."
As a consequence, a whole clutch of characters see their storylines play out amid the on-screen carnage.
The men of Lake-town, with their homes destroyed by Smaug the dragon, take refuge in the ancient town of Dale and Bard the Bowman (played by actor Luke Evans) leads them in defence of their reclaimed homeland.
"Bard is not a man that's used to leading an army," says Evans. "He's never been in a position where he's had to fight so fiercely, but he steps up to defend his children and his people."
The mighty elf king of Mirkwood, Thranduil (Lee Pace), leads his armies against the dwarven forces before turning to fight the marauding orcs.
"Thranduil has led armies in the great battles of Middle Earth and survived," says Pace. "He's been swinging his sword for thousands of years and doesn't want to do it anymore. So it's an interesting moment when he actually lifts it again. He's a force to be reckoned with."
Thranduil's feisty subject, Tauriel (Evangeline Lilly), also fights fiercely as she bids to defend the dwarf with whom she has fallen in love.
"Slaying orcs is what she lives for," says Lilly of Tauriel, who is aided in her combat scenes by the evergreen Legolas (Orlando Bloom).
"Legolas sees some pretty epic combat and Peter has built in these brilliant action moments for him," says Bloom with a beam, "like when he's hanging upside down from a giant bat."
The dwarves, too, plunge into combat and the would-be King Under The Mountain, Thorin Oakenshield (Richard Armitage), engages in a fierce standoff with the cruel orc leader, Azog the Defiler.
Even little Bilbo Baggins (Martin Freeman) takes up arms, wrapped in his magical chainmail shirt.
"Miraculously, Bilbo has learnt how to defend himself," Freeman says. "And this is an epic battle, involving hundreds of thousands of combatants, but the fun bit for me is when you see the human or Hobbit moments within all his fighting.
"Peter presents war as something that is terrible and tragic," the actor concludes. "You see the actual cost of this war and what each of the characters is fighting for."