The cross of iron sat on her chest as she moved between the beds, a decoration given to her by the very men she was betraying. Marte Knocaert wore it with the same composure she wore everything else, the neat nurse’s uniform, the calm eyes, the steady hands that dressed wounds and measured fevers while her mind recorded everything else: the numbers of a unit, the name of an officer, the careless remark about a train schedule or a new artillery piece. She had worn that cross through months of quiet, dangerous work, and it had protected her. It was the perfect disguise, a symbol of enemy trust that let her walk where no Belgian civilian should have been able to walk.
Now, in November 1916, it had become something else. The Germans knew who she was. The medal that had shielded her now marked the depth of her treachery, and the men who had pinned it on her uniform were deciding whether to shoot her. To understand how she came to that moment, it is necessary to go back to the beginning of the war, to the country that was crushed beneath the first wave of the German advance.
Belgium had declared neutrality, but that counted for nothing against the Schlieffen Plan, the German strategy that required a rapid march through Belgian territory to outflank the French armies. In August 1914, German troops crossed the border, ignoring the treaties that guaranteed Belgian independence, and the shock of the invasion rolled across Europe. Marte Knocaert was twenty-one years old, born on October 28, 1892, in the quiet village of Westrozebeke in West Flanders. She had been studying medicine at the University of Ghent, dreaming of a life devoted to healing, when the war arrived and tore that future apart.
Her town, Roeselare, an important textile center, fell quickly under German occupation. The life she had known disintegrated. The occupation brought restrictions, forced requisitions, and the constant, hated presence of enemy soldiers on the streets. The civilian hospital of Roeselare was converted into a German military hospital, a place to treat the wounded of the Kaiser.
It was there that Marte, driven by a sense of humanitarian duty and the need to find purpose in the chaos, offered her services as a volunteer nurse. She was fluent in Flemish, French, German, and English, a mark of her fine education and, in the tense multicultural atmosphere of the hospital, an essential tool. At first, it simply made her better at her job, letting her understand and comfort soldiers of many nationalities, including the Germans themselves. She was seen as competent and compassionate, a calming presence.
But that position, that privileged access to the daily workings and private conversations of an enemy military institution, made her something else entirely: a potentially priceless asset in the invisible war of intelligence. The Belgian resistance had been crushed militarily, but it simmered in the shadows, desperate for any chance to undermine the occupier. The British intelligence services, starved for information from inside occupied territory, were watching for exactly the kind of opportunity Marte represented. Who would suspect a young nurse praised for her dedication, moving freely through corridors where secrets were whispered and documents lay momentarily unguarded?
The recruitment approach came, according to accounts, through Louise Del Donck, a neighbor and friend, and Célestine Delfosse, a vegetable seller who already worked as a vital link in the Allied spy network. Marte’s decision was not impulsive. She understood the monumental risks: torture, summary execution, danger not only to herself but to her family. But the patriotic fervor, the daily sight of oppression, and the chance to actively work for the liberation of her country weighed heavier.
In 1915, the nurse gave way in the shadows to Laura, agent number 63 of the Anglo-Belgian intelligence network, the Service de Renseignement de l’Armée Belge, the intelligence service of the Belgian army, which worked in close cooperation with the British MI6. Her routine at the hospital became a ballet of deception. While she measured fevers and changed dressings, she memorized conversations about troop movements, identified specific units, took note of important officers, watched for the arrival of new weapons, and assessed the morale of the German soldiers, a crucial indicator of enemy strength. The information she gathered was a treasure: details about the construction of new trenches, the locations of machine-gun nests, plans for artillery attacks, the arrival of reinforcements, the departure of units for other fronts.
She became a master of extracting information subtly, using her apparent innocence and her role as a caregiver to win the trust and sometimes the confidences of wounded soldiers and careless officers. Her home, a villa near an important railway junction, became a nerve center for the network. There she met other agents, received and passed along messages, often coded, using varied and creative methods to smuggle reports: messages written on the thinnest paper and hidden in bars of soap, in the linings of clothes, even in the vegetable baskets carried by her accomplices. Tension was her constant companion.
Every interaction with a German officer, every apparently innocent question, every hastily made mental note was a step through a minefield. Her facade of the dedicated nurse had to be flawless, because any slip, any hesitation, could be fatal. She lived a terrible duality, caring for men who, on the larger scale, were her enemies, knowing that the information she passed could lead to the deaths of others like them. It was an immense psychological burden, sustained only by an unshakable conviction in the rightness of her cause.
Her role went far beyond passive intelligence gathering. She became a proactive part of the resistance machinery, taking part in operations that seemed unthinkable for a nurse in occupied territory. One of the most emblematic episodes of her espionage career involved the sabotage of German communication lines and, according to some sources, help in a plan to destroy a crucial ammunition depot near Roeselare. Picture the scene: the darkness of night as a cloak, the silence broken only by the distant sound of artillery and the rapid beating of her own heart.
Using her knowledge of the terrain and information obtained inside the hospital, perhaps about guard routines or the exact location of vulnerable infrastructure, she would have provided the essential data or even helped place explosives or cut vital telegraph wires. Any error, a broken branch underfoot, a roused guard dog, an unexpected patrol, and her mission, along with her life, would be over. There was also the constant threat of German counterespionage hunting Allied agents. Marte knew she was being watched, that her every move could be analyzed.
On another occasion, she discovered a German plan to install a new, powerful long-range cannon capable of inflicting severe damage on Allied positions. The exact location of the gun and its camouflage plans were information of inestimable value. Getting that data and transmitting it required a combination of cunning, courage, and a considerable dose of luck. Perhaps she took advantage of a careless officer or found documents left momentarily unguarded during one of her shifts.
The pressure to act quickly, before the information became obsolete or the German plan was executed, was immense. She used complex ciphers and secret drop points, often involving other brave civilians who risked their lives as couriers. There were moments when the net seemed to close, when a contact was arrested or a hiding place for messages was discovered. In those moments, Marte’s ability to stay calm and adapt her methods was crucial to her survival and the continuation of her operations.
For two long, exhausting years, from 1915 to 1916, she managed to elude the sophisticated German counterespionage machine. Her network supplied a steady stream of vital intelligence to the Allies, helping to thwart enemy plans and undoubtedly saving countless lives. But luck, however resilient, has a limit. In November 1916, the web of security she had so carefully woven began to unravel.
The capture of a fellow agent, possibly a local farmer named De Bile, who also belonged to her network, and the brutality of German torture led to the revelation of other names. Marte Knocaert’s name emerged from the shadows. The dedicated nurse, the exemplary professional who moved among German officers with apparent loyalty, was exposed. And it was then that the most cutting irony of her story came into focus.
Shortly before her arrest, the Germans had decorated her with the Iron Cross, a prestigious German military medal awarded for her tireless work at the hospital, for the exceptional care she gave to wounded German soldiers. Imagine the scene: Marte, the spy, wearing the German Iron Cross on her nurse’s uniform, a symbol of honor granted by the enemy she secretly fought. It had been the supreme disguise. Now it made her betrayal even more flagrant in the eyes of her captors.
Arrested, she faced relentless interrogation and a German military tribunal. The evidence against her was overwhelming. Espionage in wartime was a capital crime, and the standard sentence was death by firing squad. Her fate seemed inexorably sealed.
In her memoirs, she would describe the cold resignation she felt upon hearing the sentence. But then came the twist that defies the simplistic logic of war. General Moritz von Bissing, the German governor-general of occupied Belgium, was the highest authority who had to ratify the death sentence. He was known for his hardness, but he was also a man who, through reports and perhaps even personal observation, knew Marte Knocaert’s reputation as an exceptionally dedicated nurse.
There are accounts that several German officers, whose lives had been saved or whose suffering had been eased by her hands, interceded in her favor, or at least expressed discomfort at the idea of executing a woman who had shown them such compassion. Caught between the duty to punish a dangerous spy and the recognition of her undeniable humanitarian value, Von Bissing made a surprising decision. He commuted Marte’s death sentence to life imprisonment with hard labor. The secret of her survival was not a daring escape, nor a last-minute prisoner exchange.
It was her own humanity, the genuine compassion she had shown even toward the enemy, that paradoxically saved her from execution. The nurse saved the spy. Marte Knocaert narrowly escaped the firing squad, but her ordeal was far from over. She spent the next two years, the remainder of the First World War, languishing in severe conditions, first in the prison of Saint-Gilles in Brussels, then in the prison of Ghent.
The harshness of captivity undermined her health but not her indomitable spirit. Finally, with the armistice of November 1918, which sealed the end of the Great War and the defeat of Germany, the prison doors opened. Marte was freed, physically weakened but with the flame of her courage still burning. Her return was that of a heroine.
Belgium, France, and Great Britain officially recognized her acts of bravery and the inestimable value of her contributions to the Allied war effort. She was awarded several prestigious decorations, including the French Legion of Honor and the coveted Order of the British Empire, a testament to the respect and gratitude of the nations she had helped defend. After the war, she married John Jock, a British army officer, and published her memoirs in 1932 under the title I Was a Spy. It became a bestseller, translated into many languages and adapted for the cinema in 1933 in the film I Was a Spy, starring Madeleine Carroll.
Her story transcended the dry accounts of military operations, revealing the human face of espionage and the extraordinary capacity of ordinary individuals to accomplish remarkable feats in times of crisis. The lesson of Marte Knocaert’s life is many-sided. She demonstrated that it is possible to fight fiercely for one’s ideals without losing the essential humanity that connects us all, even to our enemies. She embodied the resilience of the human spirit in the face of brutal adversity, proving that the actions of a single person, driven by just principles, can reverberate through history.
The compassion she showed to the wounded soldiers of the army she was betraying did not weaken her cause. It saved her life, and it remains the most unexpected chapter of her long and dangerous double life.
