The retreat from Mons was an epic of endurance for the British Expeditionary Force (BEF). In their first encounter with the Germans at the Battle of Mons on August 23rd, 1914, the British Army had given a good account of itself and inflicted severe casualties on the enemy.
The soldiers were keen to fight but their French allies had fallen back. The Germans had more than a million men on the Western Front. The British had 80,000. The British could not fight back until the French were ready and no one knew when that would be.
The BEF marched some 300km from Mons to south of the Marne, just 20km from Paris. The slog was long, dangerous and slow. Men marched in broiling summer heat, worn down by bulky equipment. They were hungry and thirsty. Sleep was a luxury, four hours a night was typical. New army boots caused agonising blisters. Many men walked in their stocking feet.
In such circumstances, thousands of men became detached from their regiments. Most eventually found their way back to their units, but others either fled across the Belgian border into neutral Holland or simply got lost.
One Connaught Rangers officer put it:“Some of them fell out and lay down in the road - it exhausted all one’s vocabulary of entreaty and abuse, and event called for a liberal use of the boot to get them going again. Even, so in spite of our efforts, I’m afraid some half dozen were left behind.”
On August 27th, 1914, the 2nd battalion of the Royal Munster Fusiliers was assigned the task of providing a rearguard action against the German 2nd Army approaching from the north. They would hold the Germans up from concealed positions just long enough and then retire from the battlefield themselves.
The 800 or so Munsters expected and prepared to be outnumbered, but they did not know just how outnumbered they would be.
By 11am, the three companies of Munsters each faced an onslaught from the German X Infantry Reserve Corps.
The Munsters inflicted terrible casualties. At one stage, the Germans drove a herd of cows in front of them to mask their assault.
Then came the order to retreat at 2pm, but unfortunately the message never got through to the battalion. They were now on their own. Dead and dying soldiers littered the battlefield of this hitherto pastoral idyll of northern France with its prosperous farmlands and meandering canals.
The situation was hopeless. At 9.15pm the melancholy task was left to Lieutenant Gower, one of only four Munsters' officers left alive, to surrender in an orchard just outside the village. Some 127 of his men had been killed and 450 would end up being taken prisoner.
Among the dead were 18 soldiers from Cork, 13 each from Kerry and Limerick and four from Clare.
The Connaught Rangers had a similar experience at the village of Le Grand Fayt on August 26th. Led by Lieutenant-Colonel Alexander Abercrombie, they provided rearguard to their brigade but were trapped in the village and eventually surrounded. Some 280 were taken prisoners, but a few stragglers got away.
The Munsters and Connaught Rangers soldiers who were executed at Iron became detached from their battalions following these battles.
The six Irishmen who were among the Iron 12 executed by the Germans were not the only Irish to be executed by the enemy. In May 1916 four British soldiers were executed in similar circumstances in the village of Villeret, just north of St Quentin.
Two of the men were Irish, Private David Martin from Newry and Private Thomas Donohoe from Beltubrid, Co Cavan. They were part of the 1st battalion of the Royal Irish Fusiliers.
The story of the Villeret Four bears many similarities to that of the Iron 12. There are resolute soldiers who refuse to surrender, brave locals who shelter them, a poignant love affair and a callous betrayal.
The ringleader of the Villeret Four was Private Robert Digby from Hampshire. He fell in love with the teenage daughter of the family who sheltered him. Their child Hélène Cornaille-Digby was born in 1915 and only died in 2005 at the age of 90.
Somebody betrayed the four men. They were arrested by the Germans. The two Irishmen and Private Willie Thorpe from Liverpool were shot the next day. Digby fled into a nearby wood. He was found by the acting mayor Emile Marié who told him that he if he did not give himself up, all the villagers would be shot.
Digby gave himself up and was executed three days later. Villeret was burnt to the ground by the Germans in 1917.
The story of the Villeret Four was the subject of a BBC radio documentary and A Foreign Field, a bestseller by the former Times Paris correspondent Ben MacIntyre.
Private John Hughes of the 2nd Royal Irish Rifles from Devlin Street, Fermoy in Cork became detached from his regiment in St Quentin and was executed along with Private Thomas Hands from Newcastle.
According to an account in the book St Quentin by historians Philip Guest and Helen McPhail, the two men walked around the prison yard in the hours up to their execution singing Irish songs.
Hughes requested that a shamrock be pinned on his breast before execution but the Germans gave him a lily instead. Both men were executed on March 8th, 1915, less than two weeks after the execution of the Iron 12.