On April 25, 1792, convicted felon Nicolas-Jacques Pelletier became the first person to be executed by the guillotine. While the guillotine became known as a ruthlessly efficient killing machine, its eponym was actually motivated by humanitarian impulses.

As the spirit of liberté, égalité and fraternité swirled through Paris in the early days of the French Revolution, Dr. Joseph-Ignace Guillotin rose before the National Assembly in 1789 to lobby for equality in a most unlikely area: capital punishment. The Parisian deputy and anatomy professor argued that it was unfair for common criminals in France to be executed by tortuous methods such as hanging, burning at the stake and breaking on the wheel while aristocratic felons had the privilege of quick decapitations, particularly if they tipped their executioners to ensure swift sword chops.

Guillotin beseeched his fellow lawmakers to follow their egalitarian principles and adopt a more humanitarian and equitable system of capital punishment whereby all criminals, irrespective of class, would be beheaded. In 1791 the National Assembly made decapitation the only legal form of capital punishment in France, but the state executioner, Charles-Henri Sanson, knew this presented practical problems. A fourth-generation executioner for whom capital punishment was the family business, Sanson warned the National Assembly that beheading by sword was an inexact science that would require dozens of skilled executioners, scores of fresh swords and a means of securing felons to guarantee quick cuts. “Swords have very often broken in the performance of such executions, and the Paris executioner possesses only two,” he wrote.

Joseph-Ignace Guillotin, who proposed the idea for the beheading machine that became known as the guillotine.
Joseph-Ignace Guillotin, who proposed the idea for the beheading machine that became known as the guillotine.

The solution was found in another of Guillotin’s ideas: a beheading machine that ensured a rapid and merciful death. “The mechanism falls like lightning; the head flies off; the blood spurts; the man no longer exists,” Guillotin told his colleagues.

While Guillotin proposed the device, Dr. Antoine Louis designed the prototype, which was originally nicknamed the “Louison” or “Louisette.” Decapitation machines dated back to ancient times, but the contraption unveiled at the Bicêtre Hospital in Paris in April 1792 was cutting-edge in more ways than one. As with many modern-day products, the testing began with animals. After Sanson cleanly severed the heads of live sheep and calves, he successfully tested the guillotine on the corpses of women and children. The cuts on male corpses were not as clean, however, and prompted a redesign. The height from which the knife dropped was increased, and the convex blade was changed to a sloping, triangular shape. (An apocryphal story popularized by an Alexandre Dumas novel has King Louis XVI suggesting the changes to the machine that would ultimately lop off his head nine months later.)

After Sanson proclaimed himself satisfied with the redesign, it was time for the rollout. A throng of curious Parisians filled the plaza outside Hôtel de Ville and watched for two hours as the guillotine, appropriately painted blood red, was assembled on a scaffold. As a special unit of soldiers under American Revolution hero General Lafayette stood guard, the man whose blood would christen the new killing machine, Nicolas-Jacques Pelletier, was paraded onto the platform.

VIDEO: The Guillotine See why this device was a preferred form of legal execution.

Judge Jacob-Augustin Moreau had sentenced Pelletier to die for robbery and murder in December 1791. The execution was stayed, however, as the means of Pelletier’s death was being developed. Although Pelletier may not have agreed, Judge Moreau had implored the French minister of justice “in the name of humanity” to speed up the guillotine’s construction for the sake of the “unfortunate man condemned to death, who realizes his fate and for whom each moment that prolongs his life must be a death for him.”

Now the final moments had come. Sanson pinned the condemned man’s neck into the guillotine and released the weighted blade. Pelletier’s head dropped into a wicker basket as workers shoveled sawdust onto the blood-soaked boards. The spectacle, although quite sanguinary, was too clinical and anticlimactic to satisfy the bloodlust of the crowd. “Give me back my wooden gallows,” members of the mob chanted.

A depiction of Louis XVI’s execution by the guillotine.
A depiction of Louis XVI’s execution by the guillotine.
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In spite of the crowd reaction, the swift justice delivered by the guillotine was deemed a success. Manufacturing was ramped up to supply towns across France, and guillotines seeped into popular French culture. At fashionable dinner parties, model guillotines decapitated effigies of enemies or politicians, causing red perfume or expensive liqueurs to spew forth. Toy manufacturers even produced miniature contraptions that children used to behead dolls and live mice.

Executions by the guillotine may have been less tortuous, but they could now be carried out with the efficiency of a slaughterhouse assembly line. With the executioner now reduced to more button-pusher than craftsman, Sanson could guillotine a dozen victims in just 13 minutes. When the French Revolution morphed horrifically into the “Reign of Terror” just months after Pelletier’s execution, thousands—often without trial and with little cause—were beheaded by guillotine blades. At the height of this bloody phase, Sanson decapitated 300 men and women in just three days, and the former royal executioner even guillotined King Louis XVI on January 21, 1793. (The use of the guillotine for French executions continued until 1977. France abolished capital punishment in 1981.)

Guillotin became deeply distressed at how the device that he intended to be an example of the democratic nature and forward thinking of the French Revolution instead became a symbol of carnage and terror. Worst of all, the fatal machine will forever be attached to his name.