Stately, staid and yet somehow still satisfying, “Young Washington” is a (mostly) by-the-book biography of the early life that shaped The Father of Our Country.

It’s well-cast and handsomely mounted, and only falls into hagiography — rather obviously and clumsily — late in the third act.

This is no “Last of the Mohicans” and director and co-writer Jon Erwin (“The Jesus Revolution”) is no Michael Mann, But this action biography about Washington’s steep and stumbling learning curve into his formative years in the French and Indian War paints a revealing if not vivid flesh-and-blood portrait of a class-conscious kid who sought to better himself in the heirarchy of British Colonial America.

And it reminds us that his “big break” was bungling Britain into history’s first “World War,” The Seven Years War between Britain and the France, a globe-spanning conflict triggered by an overreaching young man’s mishandling of a frontier encroachment in the Ohio River Valley.

William Franklyn-Miller takes on the daunting task of plaaying Washington, long and lean and barely out of his teens when he talked himself into the orbit of one of the richest men in the Virginia colony, Lord Fairfax (Kelsey Grammer, perfectly cast) which put him in a position to win the ear of Governor Dinwiddie (Ben Kingsley, formidable as ever).

“Is it a sin to seek advancement,” he asks? It might be to people hellbent in ensuring their own place at the top.

Young George has made self-improvement, reading the classics and rehearsing genteel manners in the way he carries himself, his path to self-betterment. The British Army might be his one shot at such advancement.

And that’s how the young fellow whom Fairfax hired to survey his vast holdings in the Ohio wilderness found his way from messenger to militia commander “set-up,” the film implies, to take the fall when his warnings to the French to stop building forts and encroaching on British-claimed land go wrong and the first blood is shed.

“Failure is a great teacher,” he comes to learn in that first year of the French and Indian/Seven Years War.

Washington endures a steady stream of insults from assorted British officers and transplanted aristocrats, making him keenly aware of the class he was born into which his older brother Lawrence (John Foss) married his way out of, but which his widowed mother (Mary-Louise Parker) seems to accept. George remembers every slight.

He cannot hope to win the hand of the fair but self-aware rich girl Sally Clary (Mia Rodgers) unless his makes his fortune or makes his mark in the military. Or so he believes.

“Ambition waits for no man” becomes his guiding credo.

The script by Erwin, Diederick Hoogstraten and Tom Provost seeks to color in the spaces around the Red Letter dates in Washington’s early life, showing him recruiting the more woodlands-wise Christopher Gist (Leo Hanna) to join him on his surveying trip, where they meet Seneca natives and are shown — by the testy and wary Half King (Ryan Begay, quite good) where the French are settling in.

The Native Americans depicted here may take sides, but they’re mainly eager for a “Let’s you and him fight” scenario, setting these two intruder imperialist states against each other.

Slaves are mentioned but kept in the background.

Erwin handles the skirmishes and ambushes with skill, and the climactic battle, with the too-European for his own and his army’s good General Braddock (Andy Serkis at his best) comes off as chaotic and character-forming heroic.

The production design and CGI backdrops of the Virginian and Irish locations are first rate.

But the film’s dutiful “How Washington was shaped into the man he became” narrative plays as bloodless and generally humorless. Few big screen depictions of the man dare to allow him lighter moments.

“Young Washington” informs and illuminates as it passes the time between blasts of action. It’s the life, love and struggle beyond the edges of the screen, events outside of the adventures, social slights and Red Letter Dates that seems lacking.

That can’t help but hamstring this high-minded effort to capture the stumbles, failures and insults that shaped the leader whose learning curve was only completed when his endurance, pluck, experience and luck won the battle for American independence.

Rating: PG-13, violence

Cast: William Franklyn-Miller, Ben Kingsley, Mary-Louise Parker, Mia Rodgers, John Foss, Ryan Begay, Kelsey Grammer and Andy Serkis.

Credits: Directed by Jon Erwin, scripted by Jon Erwin, Diederick Hoogstraten and Tom Provost. An Angel Studios release.

Running time: 2:04