From Battlefield to Boardroom: How World War I Invented the Modern Wristwatch

On the morning of July 1, 1916, along a seventeen-mile front in the chalky farmland of northern France, tens of thousands of British soldiers waited in their trenches for the signal to advance. At precisely 7:30 a.m., following a week-long artillery bombardment that had been heard across the English Channel, whistles blew and the men climbed over the top into the catastrophe that would become known as the Battle of the Somme. In the chaos that followed -- the deadliest single day in the history of the British Army, with nearly 60,000 casualties before nightfall -- one detail went largely unrecorded by history but would prove transformative for an entire industry: the officers who led those doomed waves timed their advances with small watches strapped to their wrists.

These were not fashion accessories. They were instruments of survival, lashed to leather straps with wire lugs, their faces protected by crude metal grilles, their dials painted with the faintly glowing radium compound that would allow them to be read in the perpetual darkness of the trenches. They were, in almost every meaningful sense, the first modern wristwatches. And the story of how they came to exist -- how an object dismissed as a woman's bauble became the indispensable tool of industrial warfare and, eventually, the most enduring symbol of masculine elegance -- is one of the great untold narratives of the twentieth century.

A Woman's Ornament

To understand the revolution that the Great War wrought upon timekeeping, one must first understand the prejudices it overturned. In the years before 1914, the wristwatch occupied a peculiar and decidedly subordinate position in the hierarchy of personal timekeeping. The pocket watch was the gentleman's instrument -- substantial, dignified, carried in a waistcoat pocket and consulted with a deliberate ritual that itself conveyed status and composure. A man of means might own a Patek Philippe or a Vacheron Constantin, a precision instrument housed in a gold hunting case, its movement finished by hand to a standard that still commands respect today. The act of withdrawing the watch, thumbing open the case, and reading the time was a performance as much as a practical act.

Wristwatches, by contrast, were considered the province of women. The earliest examples were essentially miniaturized pocket watches fitted into decorative bracelets -- jewelry first, timekeepers second. Patek Philippe delivered what is often cited as the first purpose-built wristwatch to the Countess Koscowicz of Hungary in 1868, a delicate piece designed to be worn on a bracelet. Girard-Perregaux produced a series of wristwatch-bracelets for officers of the German Imperial Navy in the 1880s, but these were exceptional curiosities, not harbingers of a revolution. A man who wore a watch on his wrist before the war would have invited the same sort of incredulous reaction as a man who carried a handbag. It simply was not done.

There were, however, early hints of what was to come. The needs of colonial warfare in the late nineteenth century -- where officers in remote, fast-moving engagements could not easily consult pocket watches while handling weapons and maps -- had begun to create demand for a more accessible timepiece. During the Second Boer War (1899--1902), British officers in South Africa improvised by fitting their pocket watches into leather "wristlets" -- essentially cupped leather straps that held a standard pocket watch against the wrist. These were clumsy affairs, prone to shifting and breaking, but they demonstrated a principle: in combat, time must be available at a glance, without requiring a free hand.

Santos-Dumont and the Aviator's Problem

The most famous pre-war wristwatch emerged not from the battlefield but from the airfield, though the underlying need was identical. In 1904, the Brazilian aviation pioneer Alberto Santos-Dumont complained to his friend Louis Cartier that he could not consult his pocket watch while piloting his experimental aircraft -- his hands were fully occupied with the controls. Cartier's response was to commission a watch specifically designed for the wrist: a square-cased timepiece on a leather strap, with a prominent crown and clear, legible numerals. The resulting Cartier Santos -- produced initially as a one-off for Santos-Dumont and later offered commercially beginning in 1911 -- was arguably the first wristwatch designed for a specific masculine, practical purpose rather than as feminine adornment.

But the Santos remained a curiosity of the Parisian beau monde. It took a global conflagration to make the wristwatch universal.

The Crucible of the Trenches

The First World War was, among its many other terrible distinctions, the first war of synchronized, coordinated mass movement. The static nature of trench warfare, combined with the lethality of the machine gun and the complexity of combined-arms operations involving infantry, artillery, and later tanks and aircraft, placed an unprecedented premium on precise timekeeping. An artillery barrage had to lift at an exact, pre-arranged moment for the infantry advance to begin. If the infantry went over the top too early, they walked into their own shells. Too late, and the enemy had time to emerge from their dugouts and man their machine guns. The margin for error was measured in seconds, and the consequences of failure were measured in lives.

Pocket watches were entirely inadequate for this environment. A soldier in a front-line trench was burdened with a rifle, ammunition, grenades, a gas mask, wire cutters, and any number of other implements. His hands were never free. His clothing was caked with mud, making the retrieval of a pocket watch from beneath layers of sodden wool a practical impossibility. And in the darkness of a pre-dawn attack or a midnight trench raid, he needed to read the time without fumbling with a case or striking a match that might draw a sniper's attention.

The military establishment, characteristically, was slow to adapt. The British War Office did not initially issue wristwatches as standard equipment. Instead, officers -- who were expected to provide much of their own kit -- began purchasing them privately. The London firm Mappin & Webb was among the first to market watches specifically for military use, advertising "campaign watches" as early as 1898. By 1914, Wilsdorf & Davis (the firm that would later become Rolex), the Swiss manufacturer Zenith, and the British retailer H. Williamson Ltd. were all producing or selling wristwatches designed for military officers. The Horological Journal, the trade publication of the British Horological Institute, noted in 1917 that the wristwatch had become "almost a necessity" for officers on active service, a remarkable reversal of pre-war sentiment.

The Trench Watch: Anatomy of a Revolution

The trench watches of the First World War shared several distinctive features that would influence watch design for decades to come. Their dials were large and legible, with bold Arabic numerals and thick, luminous hands -- a sharp departure from the elegant but often hard-to-read Roman numeral dials of contemporary pocket watches. Most featured luminous radium-based paint on the numerals and hands, allowing them to be read in darkness. The radium was mixed with zinc sulfide to create a self-luminous compound that glowed a pale green, a technology that would remain standard in watchmaking until the health consequences of radium became undeniable in the 1960s.

Many trench watches featured "shrapnel guards" -- metal grilles that covered the crystal to protect it from shrapnel and debris. These guards, typically made of silver or steel wire in a grid or radial pattern, gave trench watches their most iconic and recognizable feature. They were crude, functional, and entirely devoid of aesthetic pretension. They were also, in hindsight, among the first examples of a watch design element driven purely by the demands of a specific use case -- a principle that would later produce the Rolex Submariner's rotating bezel, the Omega Speedmaster's tachymeter scale, and the Breitling Navitimer's slide rule.

The cases were typically round, 32 to 35 millimeters in diameter -- large by the standards of women's wristwatches but small by later men's standards. They were almost universally silver or nickel, as gold was considered both impractical and inappropriate for combat use. The lugs -- the projections on the case to which the strap attaches -- were often wire loops soldered directly to the case, a simple expedient that allowed a standard round pocket watch case to be adapted for wrist wear. This wire-lug construction would eventually give way to the fixed, machined lugs of modern watches, but it remained common through the 1920s.

The movements inside these early wristwatches were, by necessity, smaller than pocket watch calibers, and this miniaturization presented significant technical challenges. A smaller movement is inherently more vulnerable to the effects of gravity, shock, and temperature variation. The balance wheel, the oscillating heart of a mechanical watch, must maintain a consistent amplitude regardless of the position in which the watch is worn -- a challenge that does not arise in a pocket watch, which spends most of its life in a single, vertical orientation. Early wristwatch movements were less accurate and less robust than their pocket watch counterparts, a deficiency that would take decades of engineering development to overcome.

The Radium Girls

The luminous dials that made trench watches readable in darkness came at a terrible human cost that would not be fully understood for years. The radium-based paint was applied by hand, typically by young women working in factories in the United States, Switzerland, and the United Kingdom. These women -- who would come to be known as the "Radium Girls" -- were instructed to lick their brushes to achieve a fine point, ingesting small quantities of radium with each stroke. The practice was considered harmless at the time; radium was widely marketed as a health tonic, added to everything from drinking water to chocolate bars.

The consequences were devastating. By the early 1920s, workers at the United States Radium Corporation factory in Orange, New Jersey, began developing mysterious illnesses -- anemia, bone fractures, necrosis of the jaw (a condition that became known as "radium jaw"), and eventually cancer. The landmark legal battle that followed, in which five workers sued the company in 1927, became a foundational case in occupational health law and led to the establishment of safety standards for handling radioactive materials. The case was instrumental in the creation of the Occupational Safety and Health Administration (OSHA) decades later.

The watch industry was slow to abandon radium. It remained the standard luminous material well into the 1960s, when it was gradually replaced by tritium (hydrogen-3), which emits lower-energy radiation and was considered safer for both workers and wearers. Tritium itself has since been largely superseded by non-radioactive alternatives like Super-LumiNova, a strontium aluminate compound introduced in the 1990s. But the legacy of radium persists: vintage watch collectors are routinely advised to handle early luminous dials with care, and watches with original radium dials are subject to specific regulations in some jurisdictions.

From Armistice to Accessory

When the war ended on November 11, 1918, millions of men returned to civilian life with a new habit: wearing a watch on their wrist. The pre-war stigma had been obliterated by four years of shared masculine experience in the most extreme conditions imaginable. A generation of men who had synchronized attacks, timed artillery barrages, and navigated no-man's-land by the glow of a radium dial were not about to revert to fumbling in their waistcoat pockets.

The watch industry recognized the opportunity immediately. Through the 1920s, wristwatch production surged as manufacturers adapted their offerings to the new reality. The decade saw rapid innovation in wristwatch design and engineering, driven by a civilian market that demanded the convenience of the wrist format but expected greater refinement, accuracy, and water resistance than the crude trench watches had offered.

The most significant technical breakthrough of the period came in 1926, when Rolex introduced the Oyster -- the first commercially successful waterproof wristwatch. Hans Wilsdorf, the founder of Rolex, had been working on the problem of sealing a watch case against moisture since before the war. The Oyster case, with its screw-down caseback and crown, represented a genuine engineering achievement. Wilsdorf, who possessed a genius for marketing equal to his engineering ambition, arranged for the English swimmer Mercedes Gleitze to wear a Rolex Oyster during her cross-Channel swim on October 7, 1927. The watch survived the immersion and Wilsdorf took out a full-page advertisement in the Daily Mail to announce the fact. It was one of the first celebrity watch endorsements in history, and it cemented the Oyster's reputation as a serious instrument.

The Automatic Revolution

The other great innovation of the inter-war period was the self-winding, or automatic, movement. The principle of using the motion of the wearer's body to wind the mainspring had been explored as early as 1770 by the Swiss-born horologist Abraham-Louis Perrelet. But it was the British watch repairer John Harwood who patented the first practical automatic wristwatch movement in 1923 and brought it to market in 1928, in collaboration with the Swiss firms Fortis and A. Schild. Harwood's design used a pivoting weight that swung back and forth with the motion of the wrist, winding the mainspring through a system of reduction gears.

Rolex refined the concept with its Perpetual rotor, introduced in 1931 -- a semi-circular weight that rotated a full 360 degrees, winding the mainspring in both directions of rotation. This design, which remains the basis of virtually all modern automatic movements, eliminated the need for the wearer to manually wind the watch, a convenience that further accelerated the wristwatch's dominance over the pocket watch. By the time of the Second World War, the transition was essentially complete. The pocket watch, which had been the universal standard of personal timekeeping for four centuries, had been relegated to a niche curiosity within a single generation.

The Long Shadow of the Trenches

The wristwatch's transformation from feminine ornament to masculine essential is one of the most remarkable shifts in the history of material culture. It was not driven by fashion, though fashion eagerly followed. It was not driven by marketing, though marketers exploited it brilliantly. It was driven by necessity -- the brutal, undeniable necessity of keeping men alive in the industrialized slaughter of the Western Front.

Every modern wristwatch, from the most affordable quartz to the most rarefied grand complication, carries within it the DNA of those crude, wire-lugged, shrapnel-guarded trench watches of 1914--1918. The luminous dial, the legible numerals, the robust case, the convenient wrist strap -- all of these features, now so fundamental that we take them for granted, were forged in the specific and terrible crucible of the First World War.

When you next glance at your wrist to check the time -- an act so instinctive, so unremarkable, that you perform it dozens of times a day without conscious thought -- consider that this simple gesture was once revolutionary. Consider that it was made possible by a generation of men who needed to know the time while their hands held rifles and their world was exploding around them. Consider that the elegant object on your wrist is, in its deepest ancestry, a tool of war that became a symbol of peace, a piece of military equipment that became the most personal of accessories, a woman's trinket that became a man's indispensable companion.

The watches have changed beyond recognition. The gesture has not changed at all. And in that continuity lies a quiet, persistent thread connecting the present to one of history's most transformative moments -- a reminder, strapped to your wrist and ticking softly, that the most enduring innovations are often born from the most desperate circumstances.