A small red poppy is worn in some Commonwealth countries as a symbol to remember the fallen from the First World War. Proceeds from the sales help ex-servicemen and women in need.

Those who were lost on the battlefields of Northern Europe in the years from 1914 to 1918 are also remembered every night with a ceremony at the Menin Gate in Belgium.

Germany's International Olympic Committee (IOC) President Thomas Bach accepted an invitation to one of the Allied memorial services a few years back.

His presence was a reminder that among the sportsmen who died in the First World War, many came from Germany and her allies.

The moment which had triggered the deadly domino effect of alliances had come in Sarajevo on June 28, 1914. Archduke Ferdinand was shot by an assassin.

The coming of war had an immediate impact on some sports.

Military and Government agents were busy requisitioning horses for the front and these sometimes included race horses. Within a few days, race meetings were cancelled and owners at Newmarket in England, among them Leopold de Rothschild, ''instructed their trainers to turn their horses out of training or send them to stud".

The Olympic Games were to have been held in Berlin in 1916.

The German authorities had even hired the great American athlete Alvin Kraenzlein to help prepare their team and the Berlin Stadium had been opened amid great fanfare in 1913.

When war came, Carl Diem, an enthusiastic sports official and educationalist, and later to organise Berlin's 1936 Olympics, remained optimistic.

''We can be reasonably sure that modern war will not last long, so that long before the dates we will celebrate the Olympic Games, peace will reign again and peoples will be united in sporting competition," he said.

Others in Germany were hostile to the prospect of welcoming those who had been their enemies. "Away with everything foreign," some said.

The stadium did stage a sporting event in 1916 but it was for soldiers and included events with machine guns and grenade throwing.

By this time, even the President of the IOC had enlisted. Baron Pierre de Coubertin was now aged over 50 and he entrusted the leadership of the Olympic Movement to the Swiss Baron Godefroy de Blonay for the duration of the conflict.

The 1916 Berlin Games never took place but as Coubertin later observed: ''An Olympiad may fail to be celebrated. Its number remains.''

So many perished in the conflict that it would be impossible to chronicle them all here, but what is striking in so many cases is the youth of those who died.

They said the war would be ''over by Christmas'' but Arpad Pedery of Hungary, a gymnastics silver medallist in 1912, was dead before the autumn of 1914. He was only 23-years-old.

Hungarian fencer Bela Zulawsky lost his life in Sarajevo in October of the first year of the war. A silver medallist in sabre at London 1908, he had risen to the rank of captain at the time of his death.

Another early casualty was Baron Karl Von Venningen Ullner Von Diepurg, who had joined the IOC as a member in 1909. At the age of 48, he went to war as a German cavalry officer and died in the autumn.

Yet sport in some nations appeared to continue as normal.

The directors of Chelsea had announced at the start of the war that football would be played at London's Stamford Bridge ''as far as possible'' and that proceeds from charity matches would be given to the Prince of Wales fund.

They also staged charity athletics on the ground. In 1915, Sheffield United even defeated Chelsea on there in the FA Cup final. So many members of the crowd wore military uniform that the match became known as the ''Khaki Cup Final".

There were many who were highly critical. One soldier had written from the front to complain of "hundreds of thousands of able-bodied young roughs watching hirelings playing football".

Another suggested that professional football players "have not in any complete way grasped their country's need".

''No doubt you can make money in this field but there is only one field today where you can get honour," Punch, a popular magazine at the time, suggested.

''What a splendid example the footballer can spread around.''

Football should be allowed to continue, some argued, but should not be "the spectacular show put on by men physically most fitted to serve their country, but let it be the school or club game of real recreation played by those too young or for genuine reasons unable to serve their country".

It was only later that the authorities realised the value to morale of matches involving the star players.

War recruitment posters in Britain often encouraged participation in what authorities described as the "Greater Game".

Edgar Mobbs, a Northampton rugby union player, had made seven appearances for England and captained the team in their victory against France in 1910.

Technically too old to receive an army commission, Mobbs formed his own group of some 264 men who formed part of a sportsman battalion which was attached to the Seventh Battalion of the Northamptonshire Regiment.

He was wounded on three occasions, twice mentioned in dispatches and awarded the distinguished Service Order in recognition of his gallantry. He reached the rank of Colonel but died along with many others at Ypres in Belgium.

His name is inscribed at the Menin Gate and also at Northampton Saints rugby club in a memorial "erected by subscriptions of admirers the world over to the memory of a great and gallant sportsman".

In 1921, the Mobbs memorial match was played between East Midlands and the Barbarians, and this has become a regular event in the calendar of the sport.

Those who enlisted were encouraged to join "Pals" battalions where friends might join up and fight alongside those they knew. The practice was widespread among football clubs.

A famous match played during the ceasefire at Christmas in 1914 has entered the folklore of the First World War.

There were many footballers among the casualties. Pierre Six played in the 1908 Olympics. In the two matches in which he appeared, his French team lost twice to Denmark and conceded 26 goals.

He died at Estree Mons in the Somme in July 1916.

Little is known about the fate of Andrey Aleksandrovich Akimov. He played in the Russian football team in 1912 but lost his life in 1916.

Great Britain had won football gold in 1912. The team included Joe Dines, originally from Norfolk in the east of the country. He had joined Ilford, then a noted team, and made such an impression that Liverpool signed him after the Olympics.

When he was awarded his commission it was with the King's Liverpool Regiment but he died leading an attack on a machine gun position.

Other footballers who lost their lives included second lieutenant Walter Tull, who died less than six months before the war ended, at the age of only 29. His father had come to England from Barbados. Walter begun his career with Clapton and moved to Tottenham Hotspur and then on to Northampton Town by the time war came. He enlisted in the Middlesex Regiment Pals Battalion.

A new play entitled Tull 100 will be performed towards the end of this month in Buckingham and at venues in the Northampton area in commemoration of his life.

By the time the Amateur Athletic Association held their Annual General Meeting in 1915, ''references were made to the losses athletics had sustained".

Among the names read out was that of Britain's Wyndham Halswelle. A career soldier, he had made his reputation as a runner while serving in the military.

He qualified for the 400 metres final at the 1908 London Olympics along with three Americans in what became one of the most controversial races of all time. The race had been physical and as they entered the last 100m, Halswelle came into contact with John Carpenter.

The judges disqualified Carpenter and ordered a re-run of the race.

The other American runners withdrew in protest and Halswelle was forced to run the race alone. He was initially reluctant to do so but eventually completed a solo lap to claim gold.

The episode left him disillusioned with the sport. He announced his retirement soon afterwards and returned to his career in the military.

A sniper's bullet ended his life at Neuve Chapelle in France in 1915.

Noel Chavasse remains one of the most distinguished British athletes.

Like Halswelle he competed in the 400m at the 1908 London Olympics. A distinguished medical doctor, he treated the wounded under fire. On one occasion he carried a badly wounded man on a stretcher across the battlefield. He also led a party to rescue a wounded man from a shell hole close to the enemy lines. He was awarded the Victoria Cross, the highest award it is possible to receive for gallantry.

When he returned to the front, he was wounded while carrying another soldier to a hospital station. Later a shell burst over his dugout and although he was treated, he eventually died of his wounds. He was posthumously awarded a bar to his Victoria Cross, a distinction given to only a very few men.

Athletics was already being widely organised in military camps where cross country was particularly popular. It was much favoured by General Sir Douglas Haig and General Sir Horace Smith-Dorrien.

They also launched an appeal for ''gloves, mufflers and woolen hosiery'' to be sent to athletes who had already joined up.

''They are fighting the battle of every athlete in this country, clubs and individuals will be desirous of joining in an expression of appreciation of their courage and endurance," it was said.

Sergeant George Hutson was held up as ''an example of how the system developed".

At the Stockholm 1912 Games, he had claimed bronze in a race described in the official report as "the most interesting, the severest and probably the finest long distance race ever seen".

The two men who finished ahead of him were the legendary Finn Hannes Kolehmainen and Jean Bouin of France. Although the exact circumstances of Bouin's death remains a mystery, it is thought that he was killed by a grenade. He is remembered in the 16th arrondissement of Paris with the Stade Jean Bouin.

Frenchman Renon Boissiere finished 13th in the Stockholm Olympic marathon. When war came he served as a sub-lieutenant in the 403rd French infantry. He was reported as missing during the battle of Ville sur Tourbe Marne and his body was never recovered.

British hurdler Laurie Anderson reached the 110m semi-finals in Stockholm. Within six months of the outbreak of war, he had been killed at Ypres aged only 25. His brother Arthur competed alongside him in 1912 and was decorated for gallantry. He survived the war.

The terrible toll included New Zealand tennis star Tony Wilding. An Olympic bronze medallist in Stockholm, he won the men's singles at Wimbledon on four consecutive occasions in the immediate pre-war years. He was killed when a shell exploded at Neuve Chapelle in 1915.

The obituary in his hometown Christchurch Press said that Wilding "carried the name of the Dominion into regions of the earth where it was probably unknown until it became associated with his fame".

In the pavilion at Lord's Cricket Ground in London, there are huge wooden memorials engraved with the names of those who died.

A painting by Albert Chevallier Tayler hangs a few metres away. It is a representation of a scene at Canterbury in Kent. Among those depicted are Kent and England cricketer Colin Blythe, often known as "Charlie". He fell in 1917. A memorial in Canterbury was unveiled in his honour and on the 100th anniversary of his falling it was re-dedicated.

"It will not be a shrine to militarism but rather a symbol of the bond between the living members of the club and those who fell," said Kent Cricket's chief executive Jamie Clifford.

At Clifton College in Bristol is the name of one Arthur Collins. He scored 628 runs in a single innings in 1899 in a school house match, a world record for any class of cricket. He died in August 1914.

Reggie Pridmore was a talented all-round sportsman who played first-class cricket for Warwickshire. He was also a skillful hockey player and was leading scorer in the gold medal winning 1908 British team.

He was a major in the Royal Horse and Field Artillery and was awarded the Military Cross for gallantry. He was serving in Italy when he died.

Lord Desborough had been the chief organiser of the 1908 Games in London. He did not go to war but his family was directly affected by the conflict. His son Julian, a poet, won the Distinguished Service Order, but died at Boulogne Sur Mer. Brother Billy fell at Ypres.

The university boat race was suspended from 1915 because so many oarsmen had already enlisted.

The Oxford College crew from Magdalene had rowed together to win fours gold in the 1908 Olympics. John Somers Smith had been part of that crew. He had become a lawyer but joined the London Rifle Brigade when war began. 

He was decorated with the Military Cross at Ypres but was killed aged only 28 on the first day of the Battle of the Somme. His body was never recovered but his name is inscribed on the memorial at Thiepval.

His older brother Richard, a veteran of two university boat races, also died in the trenches.

Duncan Mackinnon, an Olympic team-mate from 1908, was killed in action in 1917.

The French oarsman Alphonse Adrien Meignant took up rowing after completing his national service. He was part of the French coxed four in 1912. When war came he re-enlisted in his old regiment as a private, but was killed at Chapel St Eloi in Belgium in November 1914.

Alongside his brother Willi, Fritz Bartholomae had been part of Germany's bronze medal winning crew in 1912. Fritz lost his life in 1915. His unit had participated in what was described in military dispatches as "difficult but victorious fighting".

It is estimated that at least 100 Australian rules footballers died during the conflict.

Bruce Moses Farquhar Sloss, a lieutenant in the 10th Machine Gun Company, had been a star performer for South Melbourne before the war and had played for the Australian divisional team. He was only 28 when he died.

At least six lost their lives on the first day of the Gallipoli campaign in Turkey, among them Collingwood's Joseph Alan Cordner.

''Join together, train together, embark together, fight together" was the recruiting slogan  encouraging players to enlist in the ''Sportsmen's 1000".

Australian Rules matches were played as fundraisers in Britain and improvised matches were played behind the lines, a few metres away from the battlefield. One soldier wrote how these impromptu matches gave the soldiers ''fresh heart'' and ''carried their thoughts back to happy days at home".

Australian teams from many sports have since made a point of visiting the battlegrounds of Gallipoli.

An Australian Olympic champion also lost his life in the war. Swimmer Cec Healy was a founder of the surf lifesaving club at Manly and won gold in the 4x200m relay, and would probably have followed that with gold in the 100m. 

However, when Americans including the favourite Duke Kahanamoku did not turn up for the semi-final, Healy insisted they be allowed to race and Kahanamoku duly qualified before taking gold in front of the Australian in silver. When war broke out, Healy enlisted in the Australian Imperial forces and served in Egypt, France and finally at the Somme, where he died leading an advance.

Although the United States did not enter the war until after the sinking of the Lusitania in 1916, they sustained many casualties.

Arthur Yancey Wear, who had played tennis at the 1904 St Louis Games, had risen to the rank of captain in the second battalion of the 356th Infantry. Although suffering from a stomach ulcer, he refused orders to return home and tragically lost his life a week before the armistice.

It was particularly heartbreaking that so many perished when the end was finally in sight. Among them were Hungary's Olympic athlete Imre Mudin, who participated in throwing events. He competed in both 1908 and 1912 and was also a prolific butterfly collector, but died in the final months of the war.

The impact of the conflict was long and lasting.

Hermann von Boninghausen had represented Germany at long jump and the 110m hurdles and was part of the team for the 1908 and 1912 Games.

His war service was as a surgeon with the 5th Lancers and the 7th Infantry. He was wounded in the face in the closing months of the war.

Although he was eventually sent home, such was the seriousness of his injuries that he died in January 1919. He is believed to have been the last direct casualty of the war. Many suffered from shellshock or what has now become known as post-traumatic stress.

Philip Noel Baker was one who survived the war. He had competed in the Olympic Games in both 1912 and 1920. A quaker, he later became a Government Minister in Great Britain and was awarded the Nobel Peace Price. He once said that he hoped the Olympics would "turn the mind of mankind to cooperation".

The mood in the aftermath of the war was not conciliatory.

The Australian forces cricket team took part in ''victory'' Test matches and inter-Allied sports events were organised at the Pershing Stadium in 1919.

The war had put paid to the ambitions of Budapest to host the Olympics. They had been hosts of an IOC Session in 1911 and seemed prime candidates for 1920.

That changed after the war. Germany and the Austro-Hungarian Empire were considered the defeated powers and as such they were excluded from the Games in the immediate post-war era.

British official Sir Theodore Cook, a member of the 1908 Organising Committee, resigned his IOC membership. He could not see any reconciliation with the Germans.

"It seemed to me that sport with Germany as a comrade had become impossible, and that the Games without her could neither be called Olympic or described as open to the world," he said.

The Games did resume in the Belgian city of Antwerp in 1920. Germany and her allies were excluded but Cook's assessment was that the decision to award them to Belgium was flawed.

It was, he said, "perhaps the most fatal stroke ever given to the Movement". 

"It associated with sport matters which had nothing whatever to do with it," he added.

There were many who wore military uniform at the Opening Ceremony of those  Antwerp Olympic Games of 1920.

Officials laid wreaths in honour of those who had perished. In 1924, the Prince of Wales was among those who took part in the ceremony.

In Los Angeles, they built a huge stadium and named it in memory of those who had lost their lives in the First World War. In 1932, the Los Angeles Memorial Coliseum staged the Olympic Games and would do so again in 1984. It will also play a central role when the Games return to the City of Angels in 2028.