One of the worst wars in human history was World War I.

Millions of soldiers and civilians died in a conflict that changed the way war was waged and paved the way for the rest of the 20th century.

For one night and one day, the armies of France and Britain on one side and Germany on the other put their weapons down to celebrate a holiday that brought them together.

The war was supposed to end by Christmas of 1914. Five months after the war started, the front was not able to agree on anything. The Battles of Tannenberg, the Marne, and Ypres caused the opposing sides to go to war.

Soldiers on both sides of the Western frontline celebrated Christmas as best they could. In no man's land, the frontline fighters began to leave their trenches without their weapons.

An amazing episode took place. The emies who were just hours before slaughtering each other were talking, singing, dancing, and eating together as if they were friends.

Christmas_Truce_1914
British and German troops meeting in No-Man's Land during the unofficial truce, 1914.
Wikimedia Commons

Soldiers wrote to newspapers and loved ones about how a truce happened.

"During Christmas Day our fellows and the Saxons fixed up a table between the two trenches and they spent a happy time together and exchanged souvenirs and presented one another with little keepsakes," wrote a British soldier.

A British soldier said in a letter to his family that he wouldn't have spent Christmas in the trenches. After establishing a truce, the soldier said that within five minutes the ground between the opposing trenches was full of Germans and Highlanders exchanging cigars and cigarettes.

In some places, soccer games were held against each other, and sometimes with mixed teams.

Both sides of the war had Christmas services as if they were in a church.

The best way to sum up the truce was said by a British soldier in his letter to the journal.

He wrote that "all this talk of hate, all this firing at each other that has raged since the beginning of the war soothed and stayed by the magic of Christmas." It is a great hope for future peace when two great nations hate each other, one side vows eternal hate and vengeance, and the other side wishes each other a Merry Christmas.

Lora Vogt, the Curator of Education at the National WWI Museum and Memorial, told Insider that it speaks to the common humanity in the midst of war and to the very best of who we are.

Though truces were implemented in some combat areas, they were not upheld everywhere along the Western Front, according to the Imperial War Museum.

The high command of both sides did not approve of the actions of the soldiers. There were no truces for the rest of the war because some units were punished or transferred.

British and German soldiers still get together to play soccer a century after the war started. The soldiers of 1914 prayed for peace in the trenches and now they are allies. There were soldiers from the two countries at the NATO base.

Reenactments of the event have been held in England and Belgium.

British and German troops play soccer, Afghanistan
German and British troops participate in a football match to commemorate the Christmas Truce of 1914, at the ISAF Headquarters in Kabul December 24, 2014.
Reuters
e-encators playing the British and German armies play football during a commemoration event to remember the World War one truce football match on June 1, 2014 in Saltburn-by-the-Sea, England.
e-encators playing the British and German armies play football during a commemoration event to remember the World War one truce football match on June 1, 2014 in Saltburn-by-the-Sea, England.
Photo by Ian Forsyth/Getty Images
People in military WWI uniforms watch the
People in military WWI uniforms watch the "Game of Truce", a recreation of a First World War Christmas truce football match, in Aldershot, west of London, on December 17, 2014.
BEN STANSALL/AFP via Getty Images

The National WWI Museum and Memorial has created an online exhibit with a huge collection of letters. You can see the exhibit and read the accounts here.

The original version of this post was published on December 25th, 2017.