The World War I Christmas truce.

The world says farewell to another Christmas holiday, hopefully free from violence and harm, and hopefully most relaxing after the bombardment of holiday ads, shopping, and marathon holiday movies that all seem to start earlier and earlier. But before blinking the brief moments of holiday bliss and picking up where you left off—training, deployments, inspections—there is one last Christmas story that should be told, even if you have heard it before.

Anyone who has deployed can easily understand the repetitive nature of life away from home, whether on a steel grey Navy ship, in middle of a stinging desert sandstorm, in a loud but lonely Quonset hut, or dug in surrounded by feet (or with our current weather, inches) of sometimes white snow. The days can feel monotonous and the weeks and months can feel like you’re slogging through life and that life is wet concrete. Time gets away and before you know it, the holiday season has set upon the world.

That was easily the world on a crisp, clear December morning 110 years ago, the bulk of Europe had been in the throes of World War I for six months. Along the western front, thousands of British, and German troops were slogging through the sheer misery of life in the cold, wet, dull trenches.

Yet there were still odd moments of joy and hope in the trenches of Flanders and France, and one of the most remarkable came during the first Christmas of the war, a few brief hours during which men from both sides on the Western Front laid down their arms, emerged from their trenches, and shared songs, peace, and comradeship.

Pope Benedict XV, who had taken office earlier that year, had originally called for a Christmas truce, an idea that was officially rejected. Many officers disapproved such a notion, but the soldiers, in a rare moment, initiated a truce on their own, a moment of peace just a few months into a war that would eventually claim over 15 million lives.

There are differing stories about what actually happened, but most accounts suggest the truce began with carol singing from the trenches on Christmas Eve.

One account found on the Smithsonian Magazine website says that sometime during that Christmas evening, an officer of the Royal Irish Rifles reported to headquarters: “Germans have illuminated their trenches, are singing songs and wishing us a Happy Xmas. Compliments are being exchanged but am nevertheless taking all military precautions.” Further along the line, the two sides serenaded each other with carols—the German “Silent Night” being met with a British chorus of “The First Noel“—and scouts met, cautiously, in no man’s land, the shell-blasted waste between the trenches.

In another account, Graham Williams of the Fifth London Rifle Brigade described it in even greater detail:

“First the Germans would sing one of their carols and then we would sing one of ours, until when we started up ‘O Come, All Ye Faithful’ the Germans immediately joined in singing the same hymn to the Latin words Adeste Fideles. And I thought, well, this is really a most extraordinary thing ­– two nations both singing the same carol in the middle of a war.”

The war diary of the Scots Guards records that a private “met a German Patrol and was given a glass of whisky and some cigars, and a message was sent back saying that if we didn’t fire at them, they would not fire at us.”

To this day historians continue to disagree over the specific details of the Christmas Truce. No one knows where it began or how it spread, or if, by some curious Yuletide magic, it broke out simultaneously across the trenches. However, some two-thirds of troops — about 100,000 people — are believed to have participated in the legendary truce.

While it lasted, the truce was magical, leading even the Wall Street Journal to observe: “What appears from the winter fog and misery is a Christmas story, a fine Christmas story that is, in truth, the most faded and tattered of adjectives: inspiring.”

As the soldiers returned to their trenches at dusk, in some cases summoned back by flares, but for the most part determined to preserve the peace at least until midnight. Some say there was more singing, and in at least one spot presents were exchanged. George Eade, of the Rifles, who had become friends with a German artilleryman who spoke good English, and as he left, this new acquaintance said to him: “Today we have peace. Tomorrow, you fight for your country, I fight for mine. Good luck.”