Director/writer Sam Mendes’ epic World War I film, “1917,” is based on incredibly grim stories he was told by his grandfather who’d enlisted for the British at age 17 and somehow survived to tell about it.

This genius filmmaker used a “single continuous shot” technique to craft a magnificent homage to the soldiers who fought in that horrible war, a fitting tribute to his grandfather and everyone else who had to fight in such an unbelievably tragic and senseless slaughter where over 10 million young educated men and another 10 million civilians died on western civilization’s most cultivated lands.

It was a worthy winner of the Golden Globe’s Award for Best Dramatic Movie, and is nominated for the Academy Awards’ Best Picture with 10 nominations, altogether. A powerfully haunting musical score by Thomas Newman accompanies the plight of two veritably-anonymous lance corporals who must traverse bloodied war zones to deliver a critical message to a commander at the front with thousands of lives at stake.

There is no forsaking the tension and suspense involved, nor the mangled landscapes of unbelievable but very realistic devastation. If anything, for all the blood, there was a merciful lack of blood in the scenes, where actually muddied fields and streams were deep red from being soaked in blood.

The film does not pretend to address issues of the causes or morality of the war, just an unforgettable slice demonstrating what it was really like. I had a grandfather in that war, too, and he never wanted to talk about it, not ever. My grandmother urged us not to ask.

In addition to “1917,” Peter Jackson’s 2017 monumental “They Shall Not Grow Old” film, based on enhanced actual footage of English soldiers in that war, and Steven Spielberg’s “The War Horse” (2011) have been worthy film tributes in the general 100th anniversary period, and at last a national monument to the four million Americans who fought in the last year of that conflict (100,000 losing their lives) is being planned for the nation’s capital.

So many great writings in the period following the war, the works of Ernest Hemingway, Anne Perry, Jacqueline Winspear, Charles Todd and Vera Brittain and more captured the senseless horror and its pervasive effects to the present. (A global Spanish flu epidemic after the war took as many as 100 million lives, and the Second World War, inevitable from the first, took as many as 85 million lives.) We live today in the dark shadow of those events.

Now, as the 100th anniversary has passed the four-year span of that conflict, it is to the rest of us to pass on what it was really all about, and perhaps with this more distanced perspective, a lot of the noise about endless machinations of conflicting nation states in that era can be dimmed, and very sad underlying realities can at last find clarity.

A clue to that reality is found in the form of Miranda Carter’s well-researched 2009 book, “George, Nicholas and Wilhelm: Three Royal Cousins and the Road to World War I.”

Yes, the heads of state of three of the principal adversaries in World War I (England, Germany and Russia) were blood relatives, cousins in fact, who as recently as May 1913, barely a year before the hostilities broke out, were all present at the wedding of Wilhelm’s daughter.

The three nations’ competing imperial interests notwithstanding, the one thing they all had in common was the growing threat to royalty, oligarchy and the old autocratic order by the rise of movements, born of the American revolution over a century earlier, for democratic social justice and equality.

What better way to suppress these movements than by sending their swelling ranks off to slaughter one another in a war? Angry contempt for the claims of labor and progressive currents was shared by all three royal cousins and their backers, and for all the much ballyhooed petty nationalistic causes attributed to the war, it is the unspeakable reality that, to one degree or another, it was sanctioned on all sides on the grounds that it would literally murder a whole young, rising generation advocating for democratic values.

Nicholas Benton may be emailed at nfbenton@www.fcnp.com.