Do they know it's Christmas?

To many people's surprise, a Christmas truce (or truces) between British and German troops occurred. It was not planned by politicians, nor by the churches (although Pope Benedict VI had called for a Christmas peace, to which no nation responded), nor by generals (although the British commander, Sir John French, did seem to explain it by saying that the soldiers "rejoice to split a friendly lance today and ride boot to boot in the charge tomorrow").

Despite the heavy death toll, British troops were not expecting the war to end soon. CE Montague, in his 1922 book Disenchantment, recorded that they realised "the war had to be won" and were determined to make that happen. Nonetheless, any break was welcome. The truces stemmed from the initiatives of British and German troops in the ranks, plus some junior officers. It is not known exactly where the first truce started. An early one was south of Ypres, where British troops looked across the frozen no-man's land to see a German notice board that read: "You no fight. We no fight." Men from both sides then walked out.

Elsewhere, Germans lit candles, displayed small Christmas trees and began singing carols. The British rendered their carols and soon a few soldiers ventured into no-man's land and exchanged Christmas greetings. More followed; gifts were exchanged, particularly cigarettes and food; photographs of each other's families were produced. The Cheshire Regiment slaughtered a pig and shared a meal with the other side. A few impromptu Christmas services were held. In some places, the truce provided the opportunity to locate and bury dead bodies.

On Boxing Day 1914, Henry Williamson, a 19-year-old private in the London Rifle Brigade, wrote to his mother: "In my mouth is a pipe presented by the Princess Mary ... In the pipe is German tobacco. From a German soldier. Yes a live German soldier from his own trench. Yesterday the British and Germans met and shook hands in the ground between the trenches and exchanged souvenirs. Yes, all day Xmas day and as I write. Marvellous, isn't it?"

Several football games were played, some using tin cans as the ball. Mostly, the games were between players of the same nationality but at least four involved both Britain and Germany. The Glasgow News reported one between the Argyll and Sutherland Highlanders and German troops, with the Scots winning 4-1. In another game, The Royal Welsh Fusiliers lost 2-1.

The truces mostly spread over Christmas Eve, Christmas Day and Boxing Day - shorter and longer in some places. They didn't happen everywhere, though in his book, To End All Wars, Adam ­Hochschild estimates that thousands took part in truces, along more than two-thirds of the front. The events received coverage, photographs and some approval in the British press. Hochschild continues that: "The Christmas Truce has passed into legend [which] represented, it is said, an outburst of spontaneous solidarity among ordinary, working-class soldiers that outraged higher-ups and militaries on both sides."

Two questions are raised by the Christmas truces. Was there ever any likelihood that they would bring the war to a permanent halt? And if not, did they have any effect at all?

Keir Hardie, the former Labour leader whose health was broken by the abuse he received because of his opposition to the war, saw the Christmas truce as an indication that British and German soldiers were recognising that they were bound by the same social class, that they had no quarrel with each other but rather, shared a common enemy in capitalism. If not immediately, they would eventually bring about social revolution.

No doubt Hardie exaggerated the likelihood of revolution - although it did come in Russia. But there was no chance of the truces being extended among the British troops. First, their all-powerful senior officers had no sympathy for them. In December 1915, the commanders forbade any repeat of the truces. Indeed, artillery bombardment was ordered for Christmas Eve.

Second, the officers closest to the troops nearly all came from public schools. As Peter Parker, himself educated at a public school, shows in his classic study, The Old Lie: The Great War And The Public School Ethos, many of the pupils were trained to be officers and to regard victory in battle as their main objective in life. They were geared to war not peace. In his book Wounded Leaders, Nick Duffell examines the emotional and psychological effect on boys of being separated from their parents and raised in elitist institutions, and argues that the outcome is often an aggressive arrogance which contributed to "the greatest madness known to history, the First World War".

Third, with a few exceptions, church leaders of nearly all denominations had publicly endorsed the war, and if they did preach about it at Christmas time, they were hardly likely to call for an extension of the truces. At one recruiting rally, the Bishop of London, Arthur Winnington-Ingram, shouted: "We would all rather die, wouldn't we, than have England become a German province." In another, he asked the crowd to consider what the Germans had done to Belgian women and children. It was estimated that he persuaded more than 10,000 to join the armed forces. Such preachers attempted to fill troops with a desire to fight and to kill in God's holy war.

Nearer to the men, some chaplains led Christmas services at the front with carols, prayers and readings from the gospels about the birth of Christ. But none were reported as applying the Christmas message of peace as a justification for the present truce or its extension.

By January 1915, the troops were extending trenches for the renewal of large-scale warfare. In March, Scottish forces were involved in the battle of Neuve Chapelle, in which the British sustained 11,652 casualties and the Germans 8500. The Christmas break was well and truly over.

So the truces did not promote a solidarity which resulted in permanent laying down of arms. They were not repeated. Yet they were significant, and their impact did reach Britain. Troops sent numerous letters to wives and parents rejoicing in the friendly contact with the enemy. The incidents, including photographs, were fully covered in the press - and not censored out - with approving comments from journalists.

Further, the two to three-day cessation of fighting along 27 miles probably saved many lives. Even if sniping alone had continued, then scores would have perished.

Moreover, the story still lives, and is mentioned in nearly every history of the First World War. Indeed, whole books are devoted to it, including Alan Wakefield's Christmas In The Trenches.

Not least, it did stimulate the practice of very minor and localised truces. As Richard Holmes explains in his book, Tommy: "If large-scale fraternisation was rare, small-scale contact was common" following the truces. Both sides would cease firing while collecting the dead for burial or retrieving the wounded. Stretcher-bearers would not be fired at. Some evenings, the sentries on either side came to a mutual agreement not to fire at each other. Trenches could be so close that shouted conversations could take place: conversations about their families, football results and so on. One German even asked a British private, who was about to go on leave to London, to visit his former girlfriend, an English girl he'd met before the war, when he was working in the city.

So how did the troops regard the enemy? Holmes, while acknowledging that hatred and brutality were not unknown, concludes: "Two general truths define the British soldier's relationship with his enemy on the Western Front: the first is that he generally had a high regard for the Germans, and the second that the fighting man rarely felt a high degree of personal hostility towards them." Their reason for fighting was to preserve the country where their families lived.

This is confirmed in the words of a participant. Richard Tawney, a Christian socialist and economic historian who served in the ranks, despite his privileged background, later wrote an article condemning British citizens for regarding soldiers as those who enjoyed killing Germans. "Hatred of the enemy," he wrote, "is not common among those who have encountered him."

This, from a man who suffered in one of the most bloody battles of the Somme, where he lay badly injured for 30 hours. Private Ronald Skirth, who was to write one of the most famous war autobiographies, also expressed this lack of hostility. He had not been a regular church member yet when there were breaks in the fighting he would sit in churches where his rejection of hostility would be reinforced. "The person I grew to hate more than any of my country's enemies," he wrote, "[was] the Commanding Officer." This was the public school-educated Major Thomas (later Sir) Snow, who regarded the deaths of both his men and of the enemy as of little importance.

What accounts for the high regard and lack of hostility of many British soldiers towards their German counterparts? Holmes links it to both their religion and their lack of religion. Only a minority were active church members and they felt distanced from the chaplains, who were officers. Yet most had been to Sunday schools "so that the religion of the average private soldier had been formed in the Sunday and day schools, not by adult worship in church". It is likely that many held on to basic Christian teaching of respecting and helping your neighbours - with "neighbour" meaning the public in general. Christmas still retained its importance in 1914 and may well have led troops to expressing it in a truce and in smaller ways as the war proceeded.

But it did not shape their whole lives and the chaplain, Studdert Kennedy, nicknamed Woodbine Willie, who went "over the top" with them, regretted that large numbers were very un-Christian in consorting with prostitutes and drinking.

At this Christmas time, the Sunday Herald has asked me to comment on my own religion. I stand with Richard Tawney, whose 1929 book Equality had a great influence on me as a student. With him I believe that the Christ who came at Christmas was the son of God, that he fled as a refugee to Egypt before returning to teach sharing among all in promoting a society based on love, not hate. I followed Tawney in becoming a Christian socialist and linking with socialists who are not Christians.

Of course, I realise that Christians are a minority in their views about the divine nature of Christmas. But, even if it is a myth, like many stories it conveys good values and practices. Just as the troops, whatever their beliefs, took Christmas to be a time to stop fighting and mix together in peace, so I hope that Christmas will serve as an opportunity for fellowship and respect, not just between similar groups but between those of different incomes, races and nationalities. The Christ who welcomed Samaritans, the traditional enemies of the Jews, makes the case for Britain to welcome hundreds of refugees from Syria.

Today on the Western Front, there is only one memorial that is not dedicated to those killed in war. It is a small Christmas tree retained from 1914, which stands as a symbol of a couple of days of peace.

Meanwhile, Sainsbury's has created a festive commercial which shows a young British soldier handing a chocolate bar to a friendly German. Profits from the sale of the chocolate go to the Royal British Legion and other financial gains to Sainsbury's. Of course, many private firms made money from the First World War. But this advert sanctifies it and suggests that friendly ­relationships are within reach, when the bitter truth is that the short-term truces were made within the stench of dead bodies, by soldiers who knew that before long they would be mowing each other down with machine-gun fire and ripping out their guts with bayonets.

This commercial smears chocolate over the question of whether the war could have been avoided. It does not ask why charming young men like those in the adverts still lose their lives in a world where more money is spent on arms than promoting peace.

Bob Holman is the author of Keir Hardie: Labour's Greatest Hero? (2010) and Woodbine Willie: An Unsung Hero Of World War One (2013), both published by Lion Hudson