9 Famous Battles That Changed the Course of History

In September 490 BC, a Persian force of roughly 25,000 soldiers landed on the coastal plain at Marathon, northeast of Athens, expecting an easy conquest. The Athenians sent out about 10,000 hoplites—citizen-soldiers in bronze armor—along with 1,000 allies from the small city of Plataea. The Persian commanders, confident in their superiority in archers and sheer numbers, waited. The Greek general Miltiades chose not to wait back.

He thinned his center and strengthened his flanks, then ordered his men to charge at a run across the plain—something no Greek army had done before. The Persians pushed into the thinned center, then found themselves surrounded as both flanks wheeled inward. Persian losses exceeded 6,000 men; fewer than 200 Greeks died. After the battle, the Athenian army marched back to the city in time to block a Persian naval approach, and the invasion fleet withdrew. The legend of a herald running 26 miles with news of victory came later, but the real legacy endured: Greece survived, democracy took root, and the West as we know it began to take shape.

Ten years after Marathon, Persia came back—this time with Xerxes I commanding the largest invasion force the ancient world had seen. A small Greek coalition chose to make a stand at Thermopylae, a narrow coastal pass where numbers mattered less. King Leonidas of Sparta led roughly 300 Spartans, along with 700 Thespians who refused to leave, and a few hundred others, holding the pass for several days against wave after wave of Persian assaults.

The end came when a local man named Ephialtes revealed a mountain path that allowed the Persians to surround the Greeks. Leonidas sent most of his allies away and remained with his Spartans and the Thespians, fighting until they were killed. The battle was lost—but not without consequence. The delay allowed the Greek fleet to prepare, and a later Greek naval victory at Salamis, combined with the land victory at Plataea in 479 BC, finally ended the invasion. Thermopylae became history’s most celebrated last stand, a symbol of courage against impossible odds that soldiers and leaders have invoked for 2,500 years since.

By the early 700s, the Umayyad Caliphate had swept across North Africa, crossed into Spain, and was pushing steadily north into what is now France. In October 732, somewhere between the cities of Tours and Poitiers, their forces met a Frankish army led by Charles, the military commander of the Frankish kingdoms. The battle lasted one or two days. The Frankish infantry held their ground in tight formation against the Umayyad cavalry, and the raiders eventually withdrew.

Historians debate how decisive the battle truly was—internal divisions within the Caliphate had already slowed expansion, and raiding continued afterward. But the battle stopped what had been a years-long advance, boosted Charles’s reputation enormously (he later acquired the nickname “Martel,” meaning “the Hammer”), and his family’s power eventually produced his grandson Charlemagne, who would reshape medieval Europe. The battle of Tours sits at a fork in the road of Western history, and the direction taken afterward is the world we still inhabit.

On the morning of October 14, 1066, King Harold II of England stood on Senlac Hill in Sussex with an exhausted army. He had just force-marched south after defeating a Norwegian invasion at Stamford Bridge, and now faced William of Normandy, who claimed the English crown had been promised to him. The Norman cavalry and archers wore Harold’s shield wall down through the long afternoon. Then, in the final hours, Harold was killed—tradition says by an arrow, though the details are contested—and the English defense collapsed.

William was crowned in Westminster Abbey on Christmas Day 1066, and England changed overnight. The Anglo-Saxon ruling class was swept away and replaced by Norman lords. Norman French became the language of the court, the law, and the church for the next three centuries—which is why so much of English legal and culinary vocabulary has French roots (“beef” from boeuf, “justice” from justice). It remains the last successful foreign conquest of England, and its ripples run through the English language to this day.

By June 1815, Napoleon Bonaparte had escaped exile on Elba, returned to France, and reassembled an army. On June 18, near the Belgian village of Waterloo, he faced the Duke of Wellington’s Anglo-Allied force. Wellington later called it “the nearest-run thing you ever saw in your life.” For most of the day, the French pressed hard. Wellington held his lines, losing ground slowly, waiting for the Prussians under Field Marshal Blücher, who arrived around 7:30 in the evening.

Napoleon committed his elite Imperial Guard in a final assault. When it met firm resistance and broke—the Guard had never broken before—the French army dissolved into panic. Napoleon abdicated four days later and was sent to the remote South Atlantic island of Saint Helena, where he died in 1821. The Congress of Vienna, already underway, redrew the map of Europe and established a system of alliances that produced nearly four decades of relative peace. Waterloo ended an era, and the word itself entered the language as a shorthand for any final, decisive defeat.

By the summer of 1863, the Confederate Army of Northern Virginia under General Robert E. Lee had won enough battles to believe a bold thrust into Pennsylvania might shock the North into seeking peace. From July 1 to 3, his army collided with the Union Army of the Potomac under General George Meade on the hills and fields outside Gettysburg, Pennsylvania. On the third day, Lee sent 12,500 Confederate soldiers across an open field in what became known as Pickett’s Charge. It was repulsed with catastrophic losses.

Over three days, between 46,000 and 51,000 soldiers from both armies became casualties—more than in any other battle of the war. The Confederacy lost generals, experienced officers, and men it could not replace. Lee retreated to Virginia and never again led a major offensive into the North. The same week, Vicksburg fell, giving the Union control of the Mississippi River. Lincoln traveled to Gettysburg that November to dedicate a cemetery and delivered two minutes of words that redefined what the war was about. Gettysburg didn’t end the conflict, but it ended any realistic Confederate hope of winning it.

In the summer of 1942, Hitler ordered his forces to capture Stalingrad—an industrial city on the Volga that also bore Stalin’s name, making its symbolic importance enormous for both sides. What followed was the largest and bloodiest battle of World War II. Street by street, building by building, sometimes floor by floor, Soviet and German troops fought for months in the ruins of the city. In November 1942, Soviet forces launched a counter-offensive that encircled the entire German Sixth Army of 300,000 men.

The German commander, Field Marshal Friedrich Paulus, surrendered the remaining 91,000 skeletal survivors on February 2, 1943. Total casualties across both sides exceeded 1.5 million. The historian David Glantz later wrote that “the Germans never fully recovered from it.” Before Stalingrad, Germany had been advancing in the East; after it, the Soviet Union held the strategic initiative and never relinquished it. Germany launched one more major offensive—at Kursk in July 1943—but it failed. From Stalingrad onward, the question was not whether Germany would lose but when.

Six months after Pearl Harbor, Japan controlled most of the Pacific and was still advancing. In early June 1942, Admiral Yamamoto sent a massive fleet to seize Midway Island, a strategic outpost in the central Pacific. What he didn’t know was that American codebreakers had read his plan. Admiral Chester Nimitz positioned three US carriers—the Enterprise, Hornet, and Yorktown—in ambush. Japan had four carriers: Akagi, Kaga, Sōryū, and Hiryū.

US dive bombers caught three of the Japanese carriers with their flight decks crowded with fueled and armed aircraft—extraordinarily vulnerable. All three sank within minutes of each other. A fourth, Hiryū, launched attacks that mortally wounded the Yorktown before being sunk that evening. Japan lost four carriers, 248 aircraft, and around 3,000 men; the US lost one carrier and 307 men. Before Midway, Japan had naval superiority; afterward, the fleets were roughly equal and the US began its island-hopping offensive. Midway also showed that carrier airpower had replaced battleship gunnery as the decisive force at sea—a lesson that shaped every navy that followed.

By the spring of 1944, Nazi Germany occupied most of Western Europe. The Soviet Union had been fighting in the East for three years, at enormous cost, and pressing for an Allied landing in the West to relieve pressure. On June 6, 1944—the date known ever since simply as D-Day—more than 156,000 Allied troops crossed the English Channel in the largest amphibious operation in military history. Five beach sectors along the Normandy coast of France were the objective. The fighting was fiercest at Omaha Beach, where American forces faced well-positioned German defenses on high ground and suffered around 2,000 casualties in a single morning.

By nightfall, a foothold had been secured. Within weeks, nearly a million Allied troops were ashore. Paris was liberated in August 1944. By May 1945, Germany had surrendered. D-Day wasn’t the last battle of the war in Europe—eleven more months of fighting followed—but it opened the Western Front that Nazi Germany could not sustain. The soldiers who landed on those beaches on a gray June morning came from a dozen nations and ranged in age from teenagers to middle-aged men. Many of them didn’t know the word “Normandy” before that day. Afterward, it became one of the most resonant place-names in the world.