For all its muscle, Gladiator did not revive swords-and-sandals. Now comes The Eagle to try, a harmless okay entry of Romans battling barbarians. Implications for today, or any day -- supercilious “superior” civilizations penetrating the domains of “inferior” grey-blue mud-painted indigenes -- might be read in but are unnecessary even if, by intention or not, the latter defenders of homeland are of more interest than the hero-invaders.

Adapted by Jeremy Brock from Rosemary Sutcliff’s 1954 adolescent novel, The Eagle of the Ninth, director Kevin Macdonald’s “epic” is an adventure story, a two-man quest hung on two hooks: the warhorse of enemies thrown together to bond as friends facing danger; and sons defining their relationships with their fathers, a Roman’s, a Caledonian slave’s, and a tribal prince’s with both his chieftain sire and his own young son.

Much of the core material coincidentally shaped last year’s Centurion, my ReelTalk review of which covers historical background not included again here. Both concern the sons of famous fathers, with the inciting force in this newer one that that son, Marcus Aquila (Channing Tatum), prays to double-edged “Father of my Fathers [not to] let me bring misfortune to my legion” while seeking to find the truth about his father Flavius’ (Aladár Laklóth, in flashbacks) heroism or cowardice leading the disappeared IX Legion twenty years earlier.

Whereas Neil Marshall softened his 2010 film with two women, a love-interest herbalist-witch against a bloodthirsty warrior-witch, Macdonald’s is exclusively male. The former promises hearth, coupling and therefore children; in contrast Marcus Aquila’s Purple Heart honorable discharge is to be rescinded and a new IX grouped under his command, as he and his blood brother tweak effete Roman noses and stage-exit arm in arm.

Marcus arrives at his first, requested command posting in Britain, proceeding to instill spit-and-polish discipline into the bored cynical defenders of the Roman fort. After caressing the small eagle carved by his father, he is wounded leading his men against a Druid fanatic (Lukács Bicskey).

SPOILER ALERT

Decorated, demobilized and recovering at the Calleva villa of his retired military man uncle (a smirking Donald Sutherland), on the spur of the moment he urges locals to go thumbs-up on a gladiator who has refused to defend himself. His life spared, this Esca of the Brigand tribe (Jamie Bell) is bought by the uncle and forced on the nephew as a slave. The Briton despises Romans, who directly killed his father Conoval, two brothers and, indirectly, his mother, but insists that the debt of honor ensures his faithfulness.

Loyal, but for how long? though no one can seriously doubt the answer or the outcome when, as guide and translator, he accompanies his master through Hadrian’s Wall (actually south of today’s border) into tribal territories from which Romans do not return. Marcus’ father is currently in disgrace for having lost not only his five thousand legionaries but also their golden eagle standard, but the son is stirred by rumors that the object exists as a pagan prize-totem.

The pair travel through autumnal Scottish locations -- the “Britain” scenery is actually Hungary -- and encounter ambiguous IX survivor Guern (Mark Strong), a deserter gone native. Further north, at the end of the world, they are overpowered by the littoral Seal People, after the marine mammals they hunt for food, bones, and hides. Esca presents Marcus as his Roman slave, so while the real slave Briton is fêted as a brother-hero, the real master Roman suffers the taunts, kicks and degradations of his new status, vowing to kill the other.

The Horned Seal Chief (Ned Dennehy) is a treacherous and brief stock figure, though his son and tribal heir is a most arresting Prince (Tahar Rahim). One may not buy this business about military honor, and in any case the Romans’ chance to redeem theirs is hokey. Still, the non-CGI clashes are realistic, the Seals PC-appealing; and, anyway, the center is less military than fraternal and filial. Predictable action cinema convention rather than history, The Eagle still does not lay any grievous entertainment egg. 

(Released by Focus Features and rated PG-13 for battle sequences and some disturbing images.)