What was history’s first side project?

"What was the first side project?" is actually a pretty tricky question. Ancient life wasn’t structured like today. People didn’t “clock in” and then chase passions after hours. Survival was the job. The great thinkers, inventors, and artists weren’t able to work nights and weekends on their passion projects—they were fully immersed in their work, often funded by patrons.

In ancient Greece, intellectual and artistic pursuits were considered the highest form of activity, seamlessly blending with daily life rather than existing apart from labor or leisure. Philosophers like Aristotle moved fluidly between teaching, debating, and thinking, with no rigid divide between work and passion. While this privilege was reserved for the elite—those not burdened by survival—their access to time and resources fostered a culture where ideas thrived in communal settings like forums and academies. This model showed that when people are free to explore out of curiosity and purpose, creativity flourishes naturally.

In Roman society, intellectual curiosity and practical duties were deeply intertwined, with thinkers often embodying multiple roles—soldier, poet, politician, engineer—simultaneously. There was little separation between professional responsibilities and personal interests; a general might also be an inventor, and a statesman a historian. Figures like Archimedes exemplified this blend, treating even his military inventions as diversions from his true love, mathematics. This cultural norm valued adaptability and broad knowledge, encouraging individuals to let their passions and professions fuel one another rather than keep them compartmentalized.

Leonardo da Vinci, Michelangelo, and Galileo led lives fueled by curiosity, moving fluidly across art, science, and engineering without the constraints of modern job structures. Their work was enabled by patronage from powerful families and institutions, allowing them to pursue interconnected projects that blurred the lines between disciplines. For these polymaths, there was no distinction between career and side project—every pursuit was part of a larger intellectual journey. Their creativity flowed continuously, showing that when passion and profession merge, innovation thrives. Though only a fortunate and driven few had this freedom, their contributions reshaped the boundaries of knowledge, science, and art.

Unlike Aristotle or Leonardo, Pliny the Elder (23-79 CE)—soldier, statesman, and imperial advisor—had a structured full-time job and pursued his writing of the first encyclopedia outside of it.

And, I believe, that makes him history’s first true side project creator.

Born into the Roman gentry, Pliny the Elder quickly rose through the ranks of Roman society. Military service, provincial governorships, and finally a position as close advisor to Emperor Vespasian himself. Pliny's career was the envy of his contemporaries. Before most Romans had even risen from bed, Pliny was already meeting with the emperor and setting the day's agenda for an empire that spanned three continents.

His nephew, Pliny the Younger, painted a vivid picture of these dawn meetings: "He would call upon the emperor Vespasian before daybreak—for he too was a night-worker—and then proceed to carry out whatever orders he had received." These duties weren't ceremonial; they involved military strategy, legal disputes, and provincial administration. It was a full slate that would have exhausted most men.

As a cavalry commander, provincial administrator, and later fleet admiral stationed at Misenum—a major Roman naval base located in the Bay of Naples in southern Italy—Pliny's days were consumed by the machinery of Roman governance. Court appearances, official correspondence, and military reviews filled his calendar from sunrise until the early afternoon. He navigated the complex politics of imperial Rome while maintaining the emperor's trust. This was no small feat during the tumultuous years following Nero's reign.

Yet beneath this exemplary public servant burned another ambition entirely—a private passion that would transform how future generations organized knowledge itself.

While serving Rome by day, Pliny dedicated every spare moment to creating something unprecedented: a complete record of all human knowledge, from astronomy to zoology. The result was Natural History.

Finished in 77 CE—and revised up until his death in 79 CE—Natural History was 37 volumes containing over 20,000 facts drawn from nearly 2,000 books by 200 authors. Pliny had created the world's first encyclopedia, 1,600 years before the term was coined. "It is a difficult task to give novelty to what is old, authority to what is new... and furthermore to write in such a manner as to suit readers of all classes," Pliny wrote in the preface to his masterwork. 

Natural History covered everything from meteorology to mining techniques, from the medicinal properties of herbs to the behavior of elephants. Some of his information was accurate—his descriptions of volcanic activity were later validated by geologists—but much of it was speculative or based on dubious sources.

"The Blemmyae tribe is reported to have no heads, their mouths and eyes being attached to their chests," he wrote with scholarly gravity. He described dog-headed people called Cynocephali who "bark instead of speaking," and races with a single giant foot "with which they shade themselves from the sun while lying on their backs." His dictations included earnest descriptions of salamanders "so cold they extinguish fire by their contact, in the same way that ice does," and elephants who "understand the religion of the stars, and venerate the sun and moon." What a strange, wonderful collection it was—alongside serious astronomical observations and botanical classifications, Pliny enthusiastically documented the bizarre and fantastical.

This monumental achievement wasn't produced in comfortable retirement or academic isolation, but in fleeting moments of time carved from an already demanding life. "I snatch rather than take time for this work," Pliny would say about how he found the time to work on Natural History, adding that he wrote "only during the night hours, so that you may know that I have slept none away on these compositions." 

According to his nephew, he would wake in the middle of the night—often around midnight—to begin reading and taking notes while the city slept. After working through imperial business all day, he would return to his studies in the afternoon, "as though another day had begun." Even meals weren't sacred—a servant read aloud while Pliny dined, and he dictated notes between bites. When a dinner guest once interrupted the reading to correct a pronunciation, Pliny scolded him: "Did you not catch the meaning?... We have lost more than ten lines through your interruption." To him, every moment mattered. His nephew observed that his uncle "considered all time wasted that was not devoted to study."

In Rome, he refused to walk anywhere, instead being carried in a litter so he could read while moving through the city. On finding his nephew walking somewhere one day, he chastised him, "If you were a student, you could not waste your hours like that." In winter travels, his secretary wore special gloves so that cold fingers wouldn't "rob Pliny of a moment" of study time. Even bathing—the one leisure activity most Romans indulged in—became a working session, with Pliny dictating notes while being rubbed down. He squeezed intellectual productivity from every minute of his day, transforming what others saw as necessary downtime into opportunities for learning.

Pliny described his encyclopedia as "a work not for the moment, but for all time"—and he was right. For nearly 1,500 years, Natural History remained a standard reference text across Europe. Medieval monks copied it religiously; Renaissance scientists like Leonardo da Vinci consulted it regularly; and early explorers carried Pliny's descriptions of distant lands on their voyages.

His life ended dramatically during the eruption of Mount Vesuvius in 79 CE. Ever the scientist, Pliny sailed toward the disaster to observe the phenomenon firsthand and assist in evacuation efforts. Overcome by toxic fumes from the volcano, he collapsed on the shore of Stabiae—a scholar to the last, sacrificing his life in pursuit of knowledge.

After his death, Pliny’s personal notes—160 volumes written in minuscule handwriting on both sides of the page—were seen as so valuable that a wealthy Roman offered 400,000 sesterces for them (equivalent to a high official's annual salary or $500,000-$1,000,000 today). "There never was a book so bad that some good might not be got out of it," Pliny often remarked, explaining his voracious reading and notetaking habits.

The true impact of Pliny's work wasn't just in the facts he collected (many later proven incorrect), but in the radical concept that knowledge should be systematically organized and made accessible to everyone. He democratized information centuries before the printing press, writing not for elite scholars but for farmers, artisans, and ordinary Romans.

When we consider modern online encyclopedias and digital knowledge bases, we're seeing the fulfillment of Pliny's vision—knowledge cataloged for all to access. But perhaps his most relevant legacy for today's world is his example of building something monumental alongside a demanding career.

"The life of the busy man," Pliny once noted, "is really the longest of all." By splitting his existence between public service and private scholarship, Pliny effectively lived two full lives in one—becoming both a successful Roman official and history's first great encyclopedist. Pliny the Elder stands as the original midnight scholar—proof that even the busiest person can create something of lasting value in the margins of an already full life.