BRUSSELS (Reuters) - "All the way down our lines ... Scots and Huns were fraternizing in the most genuine possible manner," Lieutenant Edward Hulse wrote to his mother after Christmas 1914. "If I had seen it on a cinematograph film I should have sworn that it was faked."
The centenary of that moment in World War One is now being celebrated as a triumph of shared humanity over the butchery that engulfed Europe, a day when troops along the Flanders front met after four months killing each other to sing carols, exchange gifts and play football in No Man's Land.
Less well known is that some British soldiers would later face punishment for an hour of friendship with their enemy.
Some of those fortunate survivors of 1914 were to pass three more Christmases in the trenches, observing no more broad truces as horrors fostered hatreds, but also because generals took pains to stamp out what they feared as a threat to "fighting spirit".
In one largely forgotten incident, a repeat of that first famous ceasefire the following year saw one of Hulse's fellow officers in the Scots Guards put on trial at a court martial.
Unlike Hulse, killed at 25 in March 1915, Captain Iain Colquhoun survived the war and recorded how he faced military punishment for again exchanging Christmas cigars with his German foe, and allowing both sides to bury their many dead.
"The Major-General (Lord Cavan) is furious about it," Colquhoun wrote on Boxing Day 1915. His commander wanted to know why specific orders had been disobeyed that there should be no repeat of the 1914 camaraderie that so shook the general staff.
On Dec. 25, 1915, the 28-year-old Colquhoun had written in his diary: "A German officer came forward and asked me for a truce for Christmas. I replied that this was impossible. He then asked for three quarters of an hour to bury his dead. I agreed.
"Our men and the Germans then talked and exchanged cigars, cigarettes etc for quarter of an hour and when the time was up I blew a whistle and both sides returned to their trenches.
"For the rest of the day ... not a shot was fired. At night, the Germans put up fairy lights ... and their trenches were outlined for miles ... It was a mild looking night with clouds and a full moon and the prettiest sight I have ever seen. Our machineguns played on them and the lights were removed."
After another 10 days on the front line near Lille, marked in the diary by shelling and sniping but also drinking and gambling with fellow aristocrats of the Guards Division, Colquhoun returned to a billet in the rear to find himself under arrest.
Charged with conduct to the prejudice of good order and of military discipline for "approving of a truce with the enemy", his five-hour trial on Jan. 17, 1916, heard evidence in person from General Douglas Haig, the British supreme commander.
Found guilty, Colquhoun escaped, however, with a reprimand.
That Prime Minister Herbert Asquith was his wife's uncle and Asquith's son was his defence counsel may have helped. He also felt the army understood the spirit of Christmas, writing:
"Everyone who knows the facts of the case all say that it was a monstrous thing that the court martial ever took place."
The case did not blight Colquhoun's career. He rose to high rank but remained popular with his troops even after the war, showing concern for the welfare of those who fought beside him like Private Alexander Macdonald -- this writer's grandfather.
(This story has been refiled to correct ages)
Editing by Giles Elgood