On November 27, 1895, Alfred Nobel signed his last will and testament at Paris’ Swedish-Norwegian Club. The 62-year-old industrialist had previously mused about using some of his personal fortune to support the work of scientists and inventors, but the document he produced described a project far more ambitious than anyone could have imagined. In fewer than 1,000 handwritten words, Nobel outlined a plan to devote the vast majority of his estate—worth around $265 million today—to a series of prizes for “those who, during the preceding year, shall have conferred the greatest benefit on mankind.” Nobel listed five awards in his will (a sixth, for economics, was added in 1968). Three were for the greatest discoveries or inventions in the fields of physics, chemistry and medicine, while a fourth was devoted to the author of the “most outstanding work” of literature. The fifth award was designated for “the person who shall have done the most or the best work for fraternity between the nations and the abolition or reduction of standing armies and the formation and spreading of peace congresses.”

While Nobel’s award fund would eventually become famous, there’s no denying that he was an unlikely source for a peace prize. As historian Oscar J. Falnes later noted, his family name was “associated not with the arts of peace but with the arts of war.” Nobel’s father Immanuel was an engineer who had run armaments factories and built underwater mines for Russia during the Crimean War. Alfred, meanwhile, was famous for developing new types of explosives. Among his 355 patents were designs for nitroglycerin detonators, blasting caps and a smokeless gunpowder called ballistite. In 1867, he had invented dynamite, which was widely used both in construction and in warfare. By the time he wrote his will, Nobel was hugely wealthy and owned nearly 100 factories that made explosives and munitions.

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What persuaded the “dynamite king” to devote his fortune to charity? Nobel never spoke publicly about the motivations behind the pledge, but many believe it was inspired by an earlier case of mistaken identity. In 1888, Nobel’s brother Ludvig had died in France from a heart attack. Thanks to poor reporting, at least one French newspaper believed that it was Alfred who had perished, and it proceeded to write a scathing obituary that branded him a “merchant of death” who had grown rich by developing new ways to “mutilate and kill.” The error was later corrected, but not before Alfred had the unpleasant experience of reading his own death notice. The incident may have brought on a crisis of conscience and led him to reevaluate his career. According to biographer Kenne Fant, Nobel “became so obsessed with the posthumous reputation that he rewrote his last will, bequeathing most of his fortune to a cause upon which no future obituary writer would be able to cast aspersions.”

The newspaper incident is often cited as the driving force behind Nobel’s philanthropy, but historians have yet to find an original copy of the “Merchant of Death” obituary. Some now dismiss the story as a myth, while others argue that it was only one of many factors that helped shape the inventor’s decision. The Nobel Foundation, for instance, notes that he may have first gotten the idea for the science prizes in 1868, when he received an award from the Royal Swedish Academy of Sciences for “important inventions for the practical use of mankind.” Nobel was also a voracious reader who spoke five languages and dabbled in writing plays and poems, and this may have sparked his interest in offering a prize in literature.

As for the peace prize, many credit its development to Nobel’s long friendship with Bertha von Suttner, an Austrian countess remembered for writing an anti-war novel called “Lay Down Your Arms.” The two first met in 1876, when Nobel—a lifelong bachelor—placed an ad in a newspaper for a “lady of mature age” to be his secretary and the supervisor of his household. The pair parted ways after Suttner got married, but they kept up a long correspondence through letters. Suttner later became one of Europe’s most prominent peace activists, and she often solicited donations from Nobel for her projects and congresses.

In his letters to Suttner, Nobel expressed contradictory opinions about war and peace. Though a pacifist at heart—he once called war “the greatest of all crimes”—he displayed little remorse about his work in the armaments industry, even predicting that more sophisticated weapons might serve as a deterrent against conflict. “My factories may well put an end to war before your congresses,” he wrote to Suttner in 1890. “For in the day that two armies are capable of destroying each other in a second, all civilized nations will surely recoil before a war and dismiss their troops.” Despite these remarks, many historians believe that Suttner’s pro-disarmament opinions eventually rubbed off on Nobel. In his book on the Nobel Peace Prize, author Fredrik S. Heffermehl argues that the inventor’s will is “conclusive evidence that Suttner had managed to convince Nobel to ‘do something’ for the peace movement.”

Whatever his reasons were for establishing his prizes, Nobel kept quiet about them during his lifetime. Almost no one knew about his plans before his death on December 10, 1896, and even then his will caused considerable controversy and confusion. Furious at having been denied the largest piece of his fortune, some of Nobel’s family members tried to have the will overturned. In Scandinavia, meanwhile, many criticized his dictate that the prizes were to be awarded without regard to nationality. It ultimately took five years before the executors of Nobel’s will were able to sort out all the legal issues, set up a foundation, and convince the designated Swedish and Norwegian institutions to accept the task of awarding the prizes.

Finally, in 1901, the Nobel Prizes were handed out for the first time. The inaugural laureates included the likes of Red Cross founder Henry Dunant, poet Sully Prudhomme and x-ray discoverer Wilhelm Conrad Röntgen. Four years later, Bertha von Suttner won the Peace Prize for her activist work and her role in inspiring Nobel. The organization the “dynamite king” willed into existence has since awarded more than 500 prizes to historical luminaries ranging from Albert Einstein and Marie Curie to Winston Churchill, Ernest Hemingway and Martin Luther King, Jr. To this day, the awards are still handed out every December 10—the anniversary of Alfred Nobel’s death.