On October 11, 1943, Dwight Eisenhower and British General Bernard Montgomery made a bet about the future of World War II. The war, Ike wagered, would be over by Christmas Day 1944—and he put £5 on it (which would be just under $100 in today's dollars). A year later, he must have felt pretty good about his chances: The Allied invasion of Normandy on June 6, 1944 had paved the way for a series of other Nazi defeats in France and neighboring countries; meanwhile, the Soviet Army was hammering away on the eastern front. Hitler's army was caught in a vice, and the screws were tightening.

Ultimately, however, Ike lost. On December 16, 1944, Hitler’s last major offensive campaign against the Western Allies began with a vengeance. Exploiting the weakly-defended Ardennes forest, the Nazis carved out a triangular slice of former Allied territory in Belgium, Luxembourg, and Germany. Hitler’s men wouldn’t be pushed back to their start point until January 25, 1945. By then, the Americans and Germans had respectively suffered around 81,000 and 100,000 casualties. Hitler had thought this attack might force the western Allies out of mainland Europe, allowing him to concentrate on beating the Soviets. Instead, it strengthened Allied resolve. Read on to find out more about what we in the States call “the Battle of the Bulge.”

1. REPORTER LARRY NEWMAN COINED THE NAME “BATTLE OF THE BULGE.”

Larry Newman was a war correspondent working on behalf of United Press International and the International News Service. On December 30, 1944, he met with American General George Patton to talk about the German counterattack. Newman wanted to give the fight a catchy name that wasn’t too formal. While looking at some war maps, he was struck by the bulging swell of German troops and coined the phrase Battle of the Bulge. Other journalists (particularly those working in the U.S.) were quick to adopt the new name. Germany’s military referred to their campaign as “The Ardennes Offensive”; the Allies officially called their response “The Ardennes Counteroffensive.”

2. HITLER’S ADVISORS THOUGHT IT WAS MISGUIDED.

The Führer’s ambitious goal was to sweep through the Ardennes and then take the port city of Antwerp, Belgium—and along the way, his advancing men would cut the Allied forces in half while decimating their ranks. Hitler believed he could negotiate favorable terms for an armistice with Britain, France, and the U.S. once Antwerp fell.

It wasn’t a foolproof strategy. Field Marshall Walther Model didn’t think the Germans had enough troops for the assault. Privately, he said the plan “doesn’t have a damned leg to stand on.” Others warned that Antwerp would be almost impossible to defend even if it was somehow captured. Hoping to change Hitler’s mind, Model and his fellow Field Marshall Gerd von Rundstedt suggested that he try to take back Aachen—a German city under Allied occupation—instead of going after Antwerp. Hitler ignored them.

Military historian Peter Caddick-Adams says the dictator’s choice was politically motivated. On July 20, 1944, Colonel Claus von Stauffenberg almost did the Führer in by hiding a bomb at one of Hitler’s strategy meetings. Though Hitler survived, he worried that the assassination attempt had raised questions about his competence as a leader—and believed that a decisive win over the Allies would heal his reputation. “The genesis of Hitler’s plans to launch the Bulge is his grappling to retain control of the direction of military affairs and prove to the Third Reich that he’s still the man at the top,” Caddick-Adams said in an interview with National Geographic.

3. GENERAL PATTON’S INTELLIGENCE OFFICER SAW IT COMING.

The narrative spun in most history books is that Germany’s Ardennes Offensive caught the Allies completely by surprise—but that’s not quite accurate.

While it's true that Generals Dwight D. Eisenhower and Omar Bradley later admitted they hadn’t foreseen the scale of Hitler’s massive attack, there was one U.S. intelligence officer who did anticipate the blow: Colonel Oscar W. Koch. A member of General Patton’s staff, Koch had been keeping track of German tank divisions throughout the winter of 1944. The colonel knew there were 15 such divisions in total, but only five of these were accounted for in early December. Where were the others? At a December 9 briefing, Koch told Patton that the Germans might be planning a huge counteroffensive through the Ardennes, just to the north of Patton’s Third Army. When the Ardennes Offensive started, Patton was ready for it and had his men pivot northwards, hammering Germany’s southern flank.

Other American generals in the region were totally unprepared. Koch’s fellow intelligence specialists had access to the same facts, but they interpreted them differently. Since Hitler had been losing ground in France and Belgium for so long, it was assumed that his western forces were basically spent. Other than Koch, almost no one thought Germany was able or willing to mount a large-scale offensive campaign. Years later, Koch wrote, “The Allied failure leading to the tragedy of the Bulge, was in evaluation and application of the intelligence information at hand.”

4. BASEBALL TRIVIA WAS SERIOUS BUSINESS AT AMERICAN CHECKPOINTS.

Both prior to and during the battle, English-speaking German troops disguised themselves in pilfered Allied uniforms and snuck behind enemy lines—and when the scheme was discovered, panic rippled through the American ranks. So at checkpoints, U.S. army units would quiz each other with pop culture questions like “Who plays center field for the Yankees?” and “What’s Mickey Mouse’s girlfriend’s name?” General Bradley once had to prove his identity by “naming the then-current spouse of a [movie star] named Betty Grable,” and another time nearly got in trouble when he correctly identified Springfield as the capital of Illinois—because the questioner was holding out for Chicago. On another occasion, Brigadier General Bruce C. Clarke was detained after he misidentified the Chicago Cubs as an American League baseball team.

5. WHEN ASKED TO SURRENDER, BRIGADIER GENERAL ANTHONY MCAULIFFE REPLIED WITH A FOUR-LETTER WORD.

By December 22, German forces had surrounded the town of Bastogne, Belgium, trapping 14,000 American soldiers and about 3000 civilians. At roughly 11:30 a.m., Nazi General Heinrich Freiherr von Lüttwitz sent four men to deliver a message to Brigadier General Anthony McAuliffe, head of the U.S. 101st Airborne Division. Explaining that the town was encircled by “strong German armored units,” Lüttwitz gave McAuliffe two hours to surrender peacefully. When he learned that the Germans wanted him to raise the white flag, McAuliffe grumbled “Nuts!” This amused some of his staffers, who persuaded him to put that little interjection in his formal reply. Here’s McAuliffe’s actual written response to General Lüttwitz:

“December 22, 1944

To the German Commander,

N U T S!

Signed,

The American Commander.”

Lüttwitz’s messengers didn’t understand the slang and were told McAuliffe was basically saying “Go to hell.” The isolated Americans in Bastogne held off the German siege until General Patton forced his way into the city with reinforcements on December 26.

6. COLD-RELATED INJURIES HIT EPIDEMIC LEVELS.

Keystone/Getty Images

“I was from Buffalo, I thought I knew cold,” Warren Spahn, a baseball Hall of Famer who served in WWII, later said. “But I didn’t really know cold until the Battle of the Bulge.”

The weather for most of the battle was, in a word, brutal. Hitler saw it as a strategic opportunity: He timed his Ardennes offensive for mid-December, to coincide with an outbreak of freezing rain, subzero temperatures, and dense fogs—conditions that would make it difficult for the Allies to use their aircraft to attack German ground divisions.

Many U.S. troops found themselves ill-equipped for the frozen hellscape. Standard-issue American combat boots were not waterproof and keeping one’s socks dry could be a challenge. (Frozen soil was another problem for Allied troops who had been ordered to dig out trenches.)

Altogether, the U.S. ranks saw more than 64,000 cases of “cold injuries” like trench foot and pneumonia during the brutal European winter of 1944-1945. Thousands of these occurred in the Bulge.

7. KURT VONNEGUT WAS CAPTURED IN IT.

Like the protagonist of his most famous book, Vonnegut—then a 22-year-old private with the U.S. 101st infantry division—was captured at the Battle of the Bulge on December 19, 1944, then taken to Dresden, where he was imprisoned at a facility called Slaughterhouse Five. “Seven Fanatical Panzer Divisions hit us and cut us off from the rest of [General Courtney Hodges’s] First Army,” he recalled in a letter to his family. “The other American Divisions on our flanks managed to pull out: We were obliged to stay and fight. Bayonets aren’t much good against tanks: Our ammunition, food and medical supplies gave out and our casualties out-numbered those who could still fight—so we gave up. The 106th got a Presidential Citation and some British Decoration from Montgomery for it, I’m told, but I’ll be damned if it was worth it.” While at Slaughterhouse Five, Vonnegut—again, like Billy Pilgrim—survived the Allied firebombing of Dresden.

8. PATTON SENT OUT THE MOST FAMOUS CHRISTMAS CARDS IN MILITARY HISTORY.

On December 14, 1944, just two days before the battle started, General Patton summoned Reverend James H. O’Neill, Chaplain of the Third Army, to his office in Nancy. By then, murky skies and heavy precipitation had reached the Ardennes and Patton recognized them as a military disadvantage. So the general asked O’Neill to come up with “a prayer for good weather.” According to Patton's memoirs, O’Neill resisted at first. “It usually isn’t a customary thing among men of my profession to pray for clear weather to kill fellow men,” O’Neill allegedly said. To this, Patton replied “Chaplain, are you trying to teach me theology, or are you Chaplain of the Third Army? I want a prayer.”

O’Neill retold the story differently. He claimed that a week earlier Patton had called and asked for a prayer, and O’Neill accepted the challenge at once. When O’Neill couldn’t find an existing prayer that fit the circumstances, he penned a new one. “Almighty and most merciful father,” it began, “we humbly beseech Thee, of Thy great goodness, to restrain these immoderate rains with which we have had to contend. Grant us fair weather for battle.” Patton had this printed on around 250,000 Christmas cards for his men. Each one also bore the following note from the General: “To each officer and soldier in the Third United States Army, I wish a Merry Christmas. I have full confidence in your courage, devotion to duty, and skill in battle. We march in our might to complete victory. May God’s blessing rest upon each of you on this Christmas Day.”

The cards went out on December 22. Within 24 hours, the skies had cleared well enough for the Third Army to proceed toward Bastogne (though there was still plenty of snow). A grateful Patton proclaimed, “That O’Neill sure did some potent praying. Get him up here. I want to pin a medal on him.” The next day, Patton presented O’Neill with a Bronze Star Medal.

9. DURING THE BATTLE, THE SOVIETS LAUNCHED A MAJOR ATTACK ON HITLER’S EASTERN FRONT.

At its zenith, the German “bulge” into Allied terrain was around 50 miles deep and 70 miles long. Hitler’s men—despite their impressive start—would lose every inch of ground they’d gained by the battle’s end date: January 25, 1945. A costly aircraft raid on New Year’s Day contributed to their defeat, as did fuel shortages and shifts in the weather. While the Bulge was shriveling away, the Red Army began its Vistula-Oder Offensive in Eastern Europe. The campaign kicked off on January 12, 1945 and would last through February 2. In it, over 2 million Soviets moved westward, taking cities like Warsaw and Krakow out of the Third Reich’s hands. The Red Army came within 50 miles of Berlin itself—and on January 27, it liberated the Auschwitz concentration camp. Unable to endure sustained pressure from the Soviets and Western Allies, Germany surrendered without condition on May 7, seven days after Hitler took his own life.

10. THE U.S. MILITARY EXPERIMENTED WITH INTEGRATION.

Some 1.2 million African-Americans served in the U.S. armed forces during World War II. They performed a wide range of duties, but in most circumstances, black combat troops weren’t permitted to fight “shoulder to shoulder” with their white counterparts. However, in response to personnel shortages in the Ardennes, General Eisenhower invited black soldiers to volunteer for service on the front lines. More than 2200 soldiers who took him up on the offer were chosen to fight. During the battle, the army set up companies consisting of both white and African-American platoons. Segregation would be reinstated once the Bulge came to a close, and Truman wouldn’t commit the armed services to integration until 1948.