Where Weed Came From: The Real Ancient History

Cannabis did not start in a California dispensary or a Colorado grow house. It is one of the oldest plants humans have ever cultivated, with a history that runs back thousands of years across Asia and outward from there. But that history is also buried under a thick layer of confident-sounding nonsense, stoner lore repeated so often it gets mistaken for fact. So here is the version that survives contact with evidence: where the plant actually came from, when people actually figured out it could get them high, which famous old stories hold up, and which ones fall apart the moment you check.

It started in East Asia

For a long time the assumption was Central Asia. It was a reasonable guess — people across that region had used the plant for thousands of years — but it was a guess, and it did not survive the genetics. In 2021, a study that sequenced more than a hundred cannabis genomes from around the world traced the plant’s origin to East Asia, in what is now China. The same work put its domestication at roughly 12,000 years ago, which makes it one of the oldest cultivated plants on record. The clear archaeological trail of cultivation runs back at least 6,000 years.

For most of those millennia, nobody was smoking anything. Neolithic farmers in China grew hemp next to their food crops and valued it for fiber and seed — rope, cloth, food. Some of the oldest pottery in China carries the imprint of hemp cord. The plant was useful long before it was interesting.

When people figured out it could get them high

This is where the popular story sprints out ahead of the evidence. People love to say humans have been getting high on cannabis for ten thousand years. The verified record is shorter and more specific. The earliest directly dated, chemically confirmed evidence of cannabis used for its psychoactive effect comes from a roughly 2,500-year-old burial site called Jirzankal, high on the Pamir Plateau in far-western China, where researchers found cannabis with elevated THC burned in wooden braziers during funeral rituals. Not a vague residue. An actual chemical signature.

The reason the older, grander claims keep collapsing is botanical: the early wild strains of the plant carried very little THC. Burning them would have produced smoke and not much else — one researcher who works in the region reported that he and his colleagues tried smoking and eating wild varieties and got nothing. Something at Jirzankal was different. The plants there tested unusually potent for their time, which is precisely why the find counts and the ten-thousand-year stories don’t.

The Scythians, Herodotus, and the tents

The most famous ancient weed story is also, conveniently, one of the true ones. Around 440 BCE the Greek historian Herodotus described a nomadic people called the Scythians who threw cannabis onto hot stones inside closed tents and inhaled the smoke, howling with pleasure. For a long time this was filed under “colorful anecdote from a writer with a reputation for tall tales.” Then archaeologists started excavating Scythian burials — most famously the frozen Pazyryk tombs in the Siberian Altai — and turned up the actual equipment: braziers, heated stones, cannabis seeds. Herodotus, it turns out, was taking notes, not making things up. The Scythians were getting high, ceremonially, more than two thousand years ago, exactly as described.

It was medicine, too, just not as early as the legend says

Cannabis also had a long career as a drug in the other sense of the word. It appears in one of the oldest Chinese pharmacopeias, a work traditionally attributed to Shennong, the legendary “father of Chinese medicine.” That attribution is where the popular version overreaches. You will read that cannabis was first prescribed around 2737 BCE by the Emperor Shennong himself, a tidy, very old, very specific date. The problem is that Shennong is a mythological figure, and the text crediting him was actually compiled centuries into the common era. The medical use is real. The god-king with the prescription pad is not.

The rest of the medical record is steadier. The Han-dynasty surgeon Hua Tuo is credited as the first physician on record to use cannabis as an anesthetic, reportedly ground into powder and mixed with wine before surgery — the Chinese word for anesthesia still carries the sense of “cannabis intoxication.” Greek and Roman physicians took it seriously as well: Dioscorides documented it in the first century CE, and Galen after him. Different cultures, same pattern — a plant treated as a tool, written down, and put to use.

How it got everywhere else

From its East Asian home, cannabis traveled the way useful plants always have, by trade and migration. It moved along the routes that became the Silk Road, spreading west and south. It put down deep roots in India, where it wove itself into religious life and is still associated with the god Shiva and consumed in ritual preparations. It reached the Middle East, Africa, and eventually Europe, used variously for fiber, medicine, or intoxication depending on who had it. Different societies took different things from the same plant. That theme never really stops.

The “drug-crazed assassins” almost certainly weren’t

One stop on that journey produced the most repeated cannabis story in Western history, and it is mostly invention. In the late eleventh century a Persian sect, the Nizari Ismailis led by Hassan-i-Sabbah from the fortress of Alamut, became known for carrying out precise political assassinations. The legend — that their leader kept them loyal by drugging them with hashish in a staged paradise garden — comes from Marco Polo, writing in the thirteenth century about a place he likely never saw and that the Mongols had already destroyed. The word “assassin” is popularly traced to hashishin, “hashish-users.” Historians have spent a long time pulling this apart. Many argue the “hashish” label was an insult flung by the sect’s enemies rather than a description of anything they did, that the drugged-killer scene was popularized by a French scholar in 1809, and that no credible contemporary source records the sect using hashish at all. A real sect, real assassinations, and a drug subplot that appears to have been bolted on afterward. It is the perfect ancient weed story: vivid, famous, and wrong.

How it reached the Americas

Cannabis is not native to the Americas. It arrived with people. European colonists brought hemp for its fiber, which is how it became a founding-era American crop. The psychoactive use that American law would later panic about arrived by other routes and later waves of migration. By the time the United States decided to go to war with the plant in the twentieth century, cannabis had already been a companion to human civilization for thousands of years on nearly every inhabited continent. The plant was old. The hysteria was new.

The takeaway

The honest ancient history of cannabis is more interesting than the myths, precisely because it is real. People grew this plant for fiber and food for millennia, used it as medicine, built rituals around it, and carried it across the world — inventing a few good stories along the way and at least one bad one. It has been useful, sacred, ordinary, medicinal, and eventually criminal, depending entirely on who was making the rules. Six thousand years of human history, and the only chapter where it counted as one of the most dangerous substances on earth is the recent one.

That recent chapter is the strange part, and we got into how it happened in How Weed Got Banned. The plant’s American story specifically, from founding crop to felony, is its own tangled tale in Hemp in America.

More real history, minus the campfire myths, at Infernal Insights.

Frequently Asked Questions

Where did cannabis originate?

East Asia, in what is now China. Genetic studies overturned the older assumption of a Central Asian origin. It is one of the oldest cultivated plants on record, with domestication estimated at roughly 12,000 years ago and clear cultivation evidence going back at least 6,000.

How long have humans actually used weed to get high?

Despite claims of ten thousand years, the earliest directly dated, chemically verified evidence of psychoactive cannabis use is about 2,500 years old, from the Jirzankal burial site on the Pamir Plateau in western China, where high-THC cannabis was burned in funeral rituals.

Did the ancient Scythians really smoke cannabis?

Yes, and it is well supported. Herodotus described them inhaling cannabis smoke in tents around 440 BCE, and archaeologists later found the braziers, heated stones, and cannabis seeds in Scythian burials, including the frozen Pazyryk tombs in Siberia.

How old is medical cannabis?

Cannabis appears in Chinese medical texts going back roughly two thousand years, and Greek and Roman physicians documented it in the first century CE. The popular claim that an emperor named Shennong prescribed it in 2737 BCE is legend — Shennong is a mythological figure, and the text crediting him was compiled much later.

Did medieval “assassins” really get high on hashish before killing?

Almost certainly not. The sect was real and so were the assassinations, but the drugged-killer story comes from Marco Polo and was popularized centuries later. Many historians argue the “hashish” label was an insult from the sect’s enemies, and no credible contemporary source records them actually using it.

Why are some ancient cannabis claims doubted?

Because the evidence for many of them is weak, and because early wild cannabis often contained very little THC, meaning it would not have produced a high even when burned. The verified psychoactive use is more recent and more specific.

Is cannabis native to America?

No. It was brought to the Americas by people, first as hemp for fiber by European colonists, with psychoactive use arriving through later migration. The plant is a newcomer to the continent compared with its long history in Asia.