The Christmas truce (German: Weihnachtsfrieden; French: Trêve de Noël) refers to a series of widespread but unofficial ceasefires along the Western Front of World War I around Christmas 1914.

In the week leading up to the holiday, French, German and British soldiers crossed trenches to exchange seasonal greetings and talk. In some areas, men from both sides ventured into no man's land on Christmas Eve and Christmas Day to mingle and exchange food and souvenirs. There were joint burial ceremonies and prisoner swaps, while several meetings ended in carol-singing. Men played games of football with one another, giving one of the most memorable images of the truce. Peaceful behavior was not ubiquitous; fighting continued in some sectors, while in others the sides settled on little more than arrangements to recover bodies.

The following year, a few units arranged ceasefires but the truces were not nearly as widespread as in 1914; this was, in part, due to strongly worded orders from the high commands of both sides prohibiting fraternization. Soldiers were no longer amenable to truce by 1916. The war had become increasingly bitter after devastating human losses suffered during the battles of the Somme and Verdun, and the incorporation of poison gas.

The truces were not unique to the Christmas period, and reflected a growing mood of "live and let live", where infantry close together would stop overtly aggressive behavior and often engage in small-scale fraternization, engaging in conversation or bartering for cigarettes. In some sectors, there would be occasional ceasefires to allow soldiers to go between the lines and recover wounded or dead comrades, while in others, there would be a tacit agreement not to shoot while men rested, exercised or worked in full view of the enemy. The Christmas truces were particularly significant due to the number of men involved and the level of their participation—even in very peaceful sectors, dozens of men openly congregating in daylight was remarkable—and are often seen as a symbolic moment of peace and humanity amidst one of the most violent events of human history.

The first five months of World War I had seen an initial German attack through Belgium into France, which had been repulsed outside Paris by French and British troops at the Battle of the Marne in early September 1914. The Germans fell back to the Aisne valley, where they prepared defensive positions. In the subsequent Battle of the Aisne, the Allied forces were unable to push through the German line, and the fighting quickly degenerated into a stalemate; neither side was willing to give ground, and both started to develop fortified systems of trenches. To the north, on the right of the German army, there had been no defined front line, and both sides quickly began to try to use this gap to outflank one another. In the ensuing "Race to the Sea", the two sides repeatedly clashed, each trying to push forward and threaten the end of the other's line. After several months of fighting, during which the British forces were withdrawn from the Aisne and sent north into Flanders, the northern flank had developed into a similar stalemate. By November, there was a continuous front line running from the North Sea to the Swiss frontier, occupied on both sides by armies in prepared defensive positions.[1]

In the lead up to Christmas 1914, there were several peace initiatives. The Open Christmas Letter was a public message for peace addressed "To the Women of Germany and Austria", signed by a group of 101 British women suffragettes at the end of 1914 as the first Christmas of World War I approached.[2][3] Pope Benedict XV, on 7 December 1914, had begged for an official truce between the warring governments.[4] He asked "that the guns may fall silent at least upon the night the angels sang."[5] This attempt was officially rebuffed.