One hundred years ago today, the bloodiest year yet in Europe’s long history was coming to its painful conclusion. On December 17, 1916, the guns fell silent around Verdun, a wrecked fortress-city in northeastern France, for the first time in 10 months.

The catastrophe had commenced on February 21, when German forces launched what was supposed to be a limited offensive around Verdun. The Western Front had grown static by the end of 1914, when the quick, decisive victories that all Europe’s armies anticipated would occur failed to materialize. Unable to achieve breakthroughs, soldiers on all sides dug in to avoid shells and machine gun fire. Soon the opposing trenches ran from the Swiss frontier all the way to the English Channel.

Throughout 1915, efforts by the French and British—especially the former, who had lost so much of their territory to the invader in the opening months of the Great War—to regain ground ended in agony, with offensives petering out against German fire and entrenchments. A year into the war, it was evident to any wise observer that the conflict had become a stalemate. Victory would come to the army that endured the brutal struggle the longest.

German generals accepted this horrific logic first, realizing that the war was now about attrition, not finesse. On the orders of Erich von Falkenhayn, Berlin’s top general, German forces initiated the Verdun offensive not to gain ground, not to break through, but simply to bleed France white. Falkenhayn correctly assessed that France would fight doggedly for Verdun, an ancient fortress-city, thereby allowing the Germans to operate a meat-grinder that would run until the enemy ran out of men.

That part of Falkenhayn’s vision worked as predicted—at least at first. Initial German advances were met with dogged resistance, and Verdun quickly became a rallying cry for all France: On ne passe pas—They shall not pass—was the national watchword that year. The fury of French counterattacks startled the Germans, and by the spring French generals had established a rotational system, moving units into the Verdun meat-grinder then getting them out before they completely collapsed. As a result, virtually every division in the French army fought at Verdun at some point in 1916.

Everything thereby went wrong for Falkenhayn. The fight around Verdun became mutually attritional. Hills and forts changed hands over and over again, with thousands of men falling on both sides in each fight, without changing anything of consequence strategically. The wrestling match Germany sought turned into a nightmare. Both armies kept at it all through the year. By the time the last French effort to regain lost ground was halted on December 17, Paris could proudly say they had kept the enemy out of Verdun.

Indeed, the front was pretty much where it had been in February. In all, the Germans had gained a few miles of shattered terrain overflowing with rotting corpses. The butcher’s bill of Verdun was like nothing ever seen. The bloodbath was so extensive that the armies lost track of their losses, many of whom disappeared in the muck and shellfire. No less than 700,000 French and German soldiers were killed, maimed or went missing in the struggle for Verdun, while some estimates place the true number north of 900,000. None dispute that at least 300,000 men were killed around Verdun in 1916. Alarmingly for the Germans, their losses had been almost as high as France’s. Falkenhayn’s plan to bleed the enemy white had bled his own forces just as badly, and he was cashiered from his top post as a result.

Germany’s great problem was that it was fighting a multi-front war, and Verdun wasn’t the only attritional slugfest it got embroiled in during 1916. On July 1, Britain launched its ill-starred offensive on the Somme river, 150 miles north of Verdun, to take pressure off their beleaguered French allies. Douglas Haig, commander of the British Expeditionary Force, has received torrents of criticism for the last hundred years for his mistakes, but the simple fact was that the BEF wasn’t ready for the job it was given on the Somme.

To allow a more recent analogy, he went to the Somme with the army he had, not the army he wanted.

Britain’s fine, but small, professional army was largely lost in the opening months of the war, and its place was taken by a million volunteers, termed the New Army. The Somme was to be their grand debut, and the reality was that most of the British divisions that went “over the top” on July 1 had scant experience of battle. They were no match for seasoned German divisions which had been fighting on the Western Front for almost two years.

That said, Haig had no choice in the matter. London faced the very real possibility that France was on the verge of collapse at Verdun, which would mean German victory in the West. Haig therefore launched his offensive, hoping for a breakthrough. To allow a more recent analogy, he went to the Somme with the army he had, not the army he wanted.

The result was a debacle. After a week of shelling German entrenchments, British infantry from 16 divisions assaulted the enemy. There was no element of surprise. Hardly any British units achieved their July 1 objectives; most fell apart under German machine gun and shellfire, caught in fields of barbed wire which all that shelling was supposed to have taken care of—but didn’t.

British losses on July 1 came to a staggering 57,500 men, with more than 19,000 killed—most of them in the first hour of the battle, as the infantry fixed bayonets and marched straight into German fire. Whole battalions disappeared in the slaughter. The catastrophe was like nothing seen before—or since—in British history. Haig lost far more men in a day than the whole British army lost in the Boer War of 1899 to 1902.

However, just as at Verdun, both sides kept at it, regardless of losses, and before long British divisions, with French help, began slowly taking ground on the Somme. These were small gains—a ruined village here, a shattered orchard there—but the Germans were growing weary. Their exhausted counterblows prevented the Allied breakthrough that Haig wanted, but were insufficient to hold ground for very long.

The resulting attritional wrestling match replicated the worst of Verdun, and by the time the Somme battle petered out in mid-November, the bill was well over a million men. British Empire casualties came to 420,000 soldiers while France lost a little over 200,000 on the Somme. German losses exceeded half a million. In all, more than 300,000 men died in all the armies, while the front moved less than five miles in nearly five months of offensives and counteroffensives.

This dismal story repeated itself on the Italian front where even promising offensives soon devolved into nightmares of attrition. Italy greedily joined the Great War in the spring of 1915 on the Allied side in the hope of gaining territory from ailing Austria-Hungary. Talking didn’t equal doing, however, and Italian efforts to break through on the Isonzo river—think Verdun in the Alps—proved a futile slaughter.

Even when the Italians finally gained real ground from the hard-pressed Austrians—who, like the Germans, were saddled with a multi-front war they were slowly losing—in early August 1916 in their sixth major offensive on the Isonzo, they hardly achieved a strategic breakthrough. The Sixth Battle of the Isonzo netted Italy the wrecked city of Gorizia and a few mountain peaks, at a cost of 100,000 men, including 30,000 dead, in a week.

Austrian losses were only half that, and soon they reestablished their defenses a couple miles east of where they had been. Italian efforts to break through those merely repeated the attritional nightmare of the first five battles of the Isonzo. Three more Italian offensives that autumn broke apart in the face of Austrian artillery and machine guns, gaining no ground worth mentioning and leaving some 150,000 men killed, maimed, or missing.

The only major offensive of 1916 that might be considered a real success is also the one least known to Western audiences. The Anglosphere in particular has scant interest in the Great War beyond the Western Front and far-flung campaigns that involve English-speakers, thereby missing a lot of the story. Winston Churchill termed the Eastern Front “the forgotten war” back in 1931, and so it remains to0 far to many Americans and Europeans.

Bad blood between Germans and Austrians followed, with top Prussians complaining about being ‘shackled to a corpse.’

The big missed story for 1916 is the Brusilov offensive, Imperial Russia’s last great success on the battlefield. Named after Aleksei Brusilov, the tsar’s best general and the architect of the victory, it began on June 4—the “glorious fourth of June” in Russian telling.

The objective of the offensive, launched in eastern Galicia—today’s western Ukraine—was the same as at the Somme: to take pressure off France at Verdun. Although the fighting had grown static in the east too, with trenches running for hundreds of miles, the sheer size of the enormous front compared to France and Flanders meant that breakthroughs might still be possible in a way they were not on the Western Front in 1916.

Brusilov also faced Austrians, not Germans. Austria-Hungary nearly lost the war in the summer of 1914 in eastern Galicia, losing more than 400,000 men—practically their whole standing army—in just three weeks. On the Eastern Front, they had been holding on, barely, ever since, with Berlin’s help. By mid-1916, Austrian generals were confident in their defenses, yet beneath the surface Vienna’s polyglot army was lagging and brittle, lacking confidence after painful defeats at Russian hands.

Importantly, Brusilov brought innovative new tactics, in particular close integration of infantry and artillery. The Austrians were caught by surprise when accurate Russian gunnery opened up on them on the morning of June 4—intelligence plainly indicating an imminent enemy offensive was ignored—and Brusilov’s artillery shattered Austrian positions all along the front. The stunned defenders were unable to resist for long and in many cases didn’t resist much at all. In the opening days of the offensive, the Austrian field army holding the key sector of the front lost 110,000 men—more than three-quarters of them as prisoners.

Before long, the panicked Austrians were in disorderly retreat before the Russian steamroller, losing terrified men by the thousands. Only the immediate infusion of German units managed to hold the front—but this was assistance that Berlin, already engaged at Verdun and the Somme, could hardly afford. Bad blood between Germans and Austrians followed, with top Prussians complaining about being “shackled to a corpse.”

German help saved Austria-Hungary and its defeated army in Galicia in the summer of 1916, and soon Brusilov’s battlefield triumph devolved into the familiar pattern of offensives begetting counteroffensives, producing nothing but mountains of corpses. By the time the brutal slugfest petered out in late September, the Austrians had lost almost a million men, including more than 400,000 taken prisoner. Brusilov had nearly knocked Vienna out of the war, having taken considerable ground in east Galicia, but not quite.

Moreover, Russia’s losses in the end were as great as Austria-Hungary’s, and morale at home began to suffer as hopes of winning the war gave way to horrific casualties. Brusilov’s victory would be Imperial Russia’s last. Less than five months after the offensive ended, Tsar Nicholas II was deposed, beginning that country’s decades-long nightmare of revolution, civil war and Communist mass repression that would make the bloodbath in Galicia seem small.

France triumphed at Verdun, in a sense, but the cost of that victory dogged the country for decades to come. In 1917, the French army mutinied rather than endure another such victory. The Germans indeed did not pass at Verdun, but the bloodbath required to halt them left France shell-shocked. The less-than-stellar performance of the French military in spring 1940, when the Germans invaded again, this time successfully, can be attributed in no small part to the lingering effects of Verdun.

The British, too, took from the Somme that they must never do it again. The horrific cost—above all the futile July 1 bloodbath—reverberates in Britain today. The 100th anniversary of the offensive’s start was commemorated this summer with sorrow and regret. It says something important that virtually all Britons have heard of the Somme but probably not one in a hundred knows anything about the Hundred Days of 1918, when Haig finally broke the back of the German army in the greatest victories in the long history of British arms, thereby winning the war.

One hundred years ago, Europe was busy killing itself and its civilization. In truth, that self-confident continent never recovered from 1916, when all participants in the Great War became fully committed to final victory—or defeat—so great was the cost of that terrible year. Such unprecedented horror created the world we are still living in today, with lingering consequences great and small.

John Schindler is a security expert and former National Security Agency analyst and counterintelligence officer. A specialist in espionage and terrorism, he’s also been a Navy officer and a War College professor. He’s published four books and is on Twitter at @20committee.