One of the main challenges when collecting entries for a timeline is sorting through the various levels of documentation available for different facts. It is quite possible to find hundreds of published articles and web documents that give a consistent date for a historical event and yet have none provide a reference to an original or verifiable source for the information.

If we ask the simple question "When was Cannabis first used?", we can choose from several different dates. The answer is based on whether we accept speculation, or want archeological evidence such as an ancient pipe, or require that the ancient pipe contain burned Cannabis residue. Or maybe what we want is the date Cannabis was first mentioned in a print publication.

This timeline is an attempt to collect a list of some of the earliest documented evidence of the use of psychoactive plants and chemicals by humans, as well as to characterize the type of evidence available for each given event. One of the key differentiations is between indirect and direct evidence. "Indirect Archaeological Evidence" is defined as archaeological evidence that does not prove that humans used the substance in question (e.g. a clay pipe). "Direct Archaeological Evidence" is defined as evidence which requires human use to exist (e.g. burned cannabis resin inside a pipe). "First-hand Reporting" is a description by a person who saw an event happen. "Second-hand Reporting" is one person's recording of another person's first-hand experience. "Third-hand Reporting of a Contemporary fact" involves someone reporting on an event they did not witness nor had they communicated with anyone who was present. "Third-hand Reporting of a Non-contemporary fact" describes someone relating a story of an event from a different time period (e.g. your father telling stories about what his great-grandfather is said to have done). The weakest of the evidence types is that of "Legend", which involves events for which no real evidence exists.

DATE		DESCRIPTION	CONTEXT
9000-6000 BCE	IAE	Betel nut (Areca catechu) dating to this period has been found at spirit cave in north Thailand. Because it was found with Piper betel leaves, with which it is traditionally used, this is thought to indicate early betel nut chewing.1
6000-4000 BCE	IAE DAE	Viticulture, the selective cultivation of grapes for wine, begins in what is present day Armenia.2 The oldest archaeological evidence of wine is residue found inside of jars from Hajji Firuz Tepe in northern Iran.3
c. 4200 BCE	DAE	At a site, known as ‘Cueva de los Murciélagos' (Bat Cave) near Albuñol in southern Spain, human remains were buried with grass bags containing, among other items, many poppy seed pods. Subsequent carbon dating established the date of the burials at around 4200 BC.4
4000-3500 BCE	IAE	Imprints of hemp textiles and cordage mark several fragments of pottery found in the ruins of Xi'an Banpo village in central China.5
3500-3100 BCE	DAE	The earliest evidence of brewing is beer residue found inside a pottery vessel at the site of Godin Tepe in the Zagros Mountains of western Iran.6	3100 BCE - Sumerians develop the first written language, cuneiform.
3000-2100 BCE	IAE	Vessel containing powdered lime (believed to have been used in conjunction with coca chewing) suggests the use of coca in Ecuador.2,7	3000-2000 BCE - Egyptians develop hieroglyphic writing.
c. 2737 BCE	L	Emperor Shen Nung of China is attributed with discovering the medicinal uses of thousands of plants. No written record exists from this period.	2600 BCE - Construction begins on the great pyramids in Egypt.
c. 2100 BCE	EIP	Sumerian tablets discussing "the joy plant" are believed by many to be the first written reference to the opium poppy.4	2500 BCE - Iron Age begins in the Middle East.
1800 BCE	EDP	The oldest known recipe, a recipe for beer, appears on a cuneiform tablet in an epic poem to Ninkasi, the Sumerian goddess of beer.8	1450 BCE - Sundial is invented by the Egyptians.
1550 BCE	EIP	One of the oldest known complete books, the Ebers Papyrus from Egypt, describes the medical use of hundreds of plants including a recommendation for what is believed by some to be the opium poppy to induce sleep. It also mentions aloe and henbane.4,9	1400 BCE - First alphabetic language is developed by the Phoenicians. These letters formed the basis of most of the written European languages.
1400-1100 BCE	IAE	Poppy goddess idol from the Myceanaean culture near Gazi on Crete bears three poppy capsules on her head.4	1400 BCE - First Mycenaean Greek writing, discovered on tablets on the island of Crete.
c. 1300 BCE	IAE	Carvings from the Chavín culture in northern Peru depict mythological beings holding the visionary San Pedro cactus.10	1340 BCE - Tutankhamun is buried in Egypt.
1200-800 BCE	TRN	Soma is described as a psychoactive ambrosia in the orally transmitted Rg Veda hymns. Modern scholars variously identify Soma as entirely mythical, A. muscaria, Cannabis, alcohol, water lily or lotus, P. harmala, and others.11,12,13	c. 1200 BCE - Written language has been developed in China.
1200-800 BCE	TRN	Bhang (dried Cannabis leaves, seeds and stems) is mentioned in the verses of the Hindu Atharva Veda as "Sacred Grass", one of the five sacred plants of India. It is described as both a medicinal and ritual offering to Shiva.
c. 1000 BCE	IAE	Mushroom stones crafted in Guatemala are believed by many to represent psychoactive mushrooms.14
c. 1000 BCE	IAE	Tubular pipes from the Marajó Islands of Brazil are believed to be some of the earliest evidence of tobacco use.15
600-250 BCE	DAE	Ceramic teapot with Cacao residue shows that the Maya of Belize drank a chocolate-containing beverage.16
400-200 BCE	IAE	A ceramic snuff pipe from this period--in the shape of a deer holding a peyote button between its teeth--is found at Monte Albán in Oaxaca, Mexico.14
500-300 BCE	DAE	A tobacco-containing pouch from this era was found at Niño Korin, Bolivia.7
430 BCE	EDP DAE	Herodotus reports on both ritual and recreational use by the Scythians of a plant believed to be Cannabis.17 Cannabis remains have also been found in Scythian tombs from this period.18	c. 350 BCE - First Greek herbal is written by Diocles of Caryotos. Only fragments remain.10
301 BCE	EDP	Theophrastus, a student of Aristotle, writes about the hallucinogenic effects of Datura stramonium. The text contains one of the earliest references to the concept of tolerance to a drug.19	c. 270 BCE - Construction begins on the Great Wall of China.
25-221	EDP	Earliest writing on the effects of hundreds of herbal medicines, including the stimulant effects of Ephedra, appear in the Pen Ts'ao attributed to the legendary Shen Nung.20,22	c. 100 BCE - First illustrated herbal, by Greek herbalist Krateuas.
65	EDP	De Materia Medica published by Dioscorides, and now considered the foundation of herbal literature, contains references to Ergot, Hyoscyamus niger (henbane), foxglove, aloe and others.21	105 - Paper as we know it was first made in China by Ts'ai Lun.
347	EDP	The earliest known reference to tea is the Erh Ya, an ancient Chinese dictionary annotated by Kuo P'o, which defines tea as "a beverage from leaves made by boiling" and describes different tastes based on when the leaves are picked.22	150 - Ptolemy publishes Geographia, which introduces latitude and longitude.
386-534	EDP	The earliest Chinese agricultural text, the Xia Xiao Zheng, mentions hemp as one of the country's main crops.23	354-430 - St. Augustine writes formative Christian theology.
500	DAE	In a tomb from the Tiahuanacoid culture of Bolivia were found flattened and bundled leaves from the Guayusa plant--the caffeine containing plant used as the source of Yerba Maté. Along with the leaves were mortar and pestle for grinding the leaves to powder, storage containers, snuff trays and tubes used for snorting the powder.24	375-500 - Roman Empire collapses and Rome is sacked by waves of northern European armies.
c. 850	L	Ethiopian legend describes the discovery of coffee beans by a goat herder named Kaldi. One night he finds his goats dancing around a shrub with red berries. After trying the berries himself, he too starts dancing.22	742-814 - King Charlemagne conquors and rules western Europe.
c. 1000-1100	TRC	Arabian doctor Ibn Sina (Avicenna) reported on Datura metel under the name ‘Jouzmathal' (metel nut) in his book As-Qanum.14
1161-1189	DAE	Earliest known distillation apparatus, made of copper and dated to this period, was found in China. There is speculation and some evidence that the Chinese knew the art of distillation much earlier.25	c. 1150 - The Physica, by Hildegarde of Bingen, is the first herbal written by a woman.
c. 1200-1400	IAE	Vienna Codex depicts the ritual use of mushrooms by the Mixtec gods, showing Piltzintecuhtli and seven other gods holding mushrooms in their hands.26	1250 - On Plants is written by Albertus Magnus.
1271-1295	SR	Journeys of Marco Polo is published, detailing second-hand reports of Hasan ibn al-Sabbah and his "assassins" using hashish. This is the first time Cannabis has been brought to the attention of Europe.27	1220-1250 - Ghengis Khan creates an empire from Hungary to China.
c. 1350	TRN	The oldest monograph on hashish, Zahr al-'arish fi tahrim al-hashish, by Az-Zarkashi, is written. It has since been lost.	1450 - The printing press is invented.
1492	FR	Two of Columbus' crew, de Jerez and de Torres, are the first Europeans to witness tobacco smoking by Native Americans.15 De Jerez becomes the first European tobacco smoker and brings the habit back to Europe. It is said that de Jerez was accused of demonic possession and imprisoned by the Inquisition after frightening a neighbor by blowing smoke from his nose and mouth. He is released years later after smoking becomes widespread in Spain.28	1483 - Apuleius' herbal, first published in 350 AD, becomes the first herbal printed on the printing press.
1496	EDP	Friar Ramon Pane, travelling with Columbus, documents the use of a psychoactive snuff called cohoba among the Taino who inhabit the island of Hispaniola (Haiti/Dominican Republic). It is now agreed that cohoba was almost certainly made from Anadenanthera peregrina, which contains N,N-DMT, 5-MeO-DMT, and Bufotenin.29
1499	EDP	First accounts of Coca use are recorded by Dominican missionary Thomas Ortiz in Venezuela in 1499.30
1519	EDP	An influential book on the distillation process, Das Buch zu Distillieren, is published in Germany by Hieronymus von Braunschweig. Distillation allowed for the concentration of herbal ingredients into medicines as well as the development of drinkable spirits such as brandy.31
1522	EDP	Betel nut chewing recorded by Pigaphetta after visiting Indonesia.32
1535	EDP	First printed reference to tobacco smoking appears in Gonzalo Fernandez de Oviedo y Valdés's Historia General y Natural de las Indias.
1560	EDP	Spanish priest Bernardino de Sahagún writes in the Florentine Codex about the use of peyote and hallucinogenic mushrooms by the Aztecs, estimating that peyote has been in use since at least 300 BCE.33,45 He later documented the ritual use of ololiuqui (morning glory) as well.34
1576	EDP	Nutmeg's inebriant effects are first recorded in a story about a pregnant woman who ate 10-12 nutmegs--in an effort to induce abortion--and became "deleriously inebriated".35
1658	EDP	Polish prisoner of war writes about the use of Amanita muscaria in a culture from Western Siberia (Ob-Ugrian Ostyak of the Irtysh region): "They eat certain fungi in the shape of fly-agarics, and thus they become drunk worse than on vodka, and for them that's the very best banquet."36	1590-1609 - first compound microscope invented in the Netherlands.
1792	EDP	Dr. Pierre Ordinaire writes a recipe for absinthe, and becomes one of the first to promote the virtues of the wormwood drink.37	1796 - First innoculations/vaccinations.
1800	EDP	Humphry Davy publishes the book, Researches, Chemical and Philosophical: Chiefly Concerning Nitrous Oxide, in which he describes inhaling nitrous oxide and obtaining a degree of analgesia from a painful condition he was suffering. Davy is responsible for coining the term "laughing gas".38	1800-1815 - Napoleon wages war across Europe.
1805	EDP	F.W. Sertürner, a German pharmacist, is credited with isolating the active ingredient of opium, which he later names morphine.39	1812 - Grimm Brothers collect German folklore.
1819	TRN	Caffeine is first isolated by German chemist Friedlieb Runge.22	1815 - Stethoscope is invented.
1831	EDP	Atropine is first isolated from Atropa belladonna by Mein.40	1844 - First intercity telegraph message is transmitted; "What hath God wrought!"
1851	EP	First Western record of the psychoactive effects of Ayahuasca (Banisteriopsis caapi or yage) in Peru and the Brazilian Amazon.41	1853 - Hypodermic syringe with a needle fine enough to pierce the skin is invented.
1850s	TRN	Cocaine is first isolated from Erythroxylon coca. Scholars dispute whether Niemann or Gaedeke was first to do this.42	1859 - Darwin & Wallace announce theory of evolution.
1864	TRN	First report of the use of Tabernanthe iboga root as a stimulant and aphrodisiac in Gabon and the Congo, made by Griffon du Bellay, who took specimens to Europe.43	1868-1873 - First typewriter is designed and produced.
1869	EDP	Sleep-inducing effects of chloral hydrate are discovered by Liebreich.44	1869 - Suez Canal opens.
1874	EDP	Heroin is first derived from morphine by C.R. Alder Wright at St. Mary's Hospital in London.39	1869 - American transcontinental railway is completed.
1887	EDP	Ephedrine is first isolated from Ephedra sinica by Japanese chemist, NM Nagai.10	1887 - First mimeograph is produced.
1889	EDP	The genus Tabernanthe is established and the botanical description of T. iboga is made by Henri Baillon at the Musée National d'Histoire Naturelle in Paris.43	1889 - Eiffel Tower built for centennial of French Revolution.
1896	EDP	Mescaline is first isolated from Lophophora williamsii (peyote) by Arthur Heffter. Heffter used self-experimentation to determine which of the chemicals isolated from peyote were psychoactive.45
1897	EDP	Heroin is synthesized by Felix Hoffman at Bayer Pharmaceutical. Bayer immediately recognizes its potential and begins marketing it heavily for the treatment of a variety of respiratory ailments. Within a few years, doctors and pharmacists begin noticing that patients are consuming large amounts of heroin-containing cough remedies.46
1903	EDP	Barbiturates are first introduced into medicine by Fischer and von Mering.47
1918	EDP	Ergotamine is first isolated from Claviceps purpurea by Stoll.48	1920 - Prohibition Amendment takes effect in the United States.
1931	EDP	N,N-DMT is first synthesized by British chemist Manske and named "nigerine".49 Notably, this synthesis predated its discovery in the plant kingdom.
1935	EDP	Amphetamine's stimulant effect is first recognized.50	1927 - First television broadcast across phone lines.
1943	FR	Albert Hofmann discovers the psychoactive effects of LSD.48
1947	EDP	First article on LSD's mental effects published by Werner Stoll in the Swiss Archives of Neurology.51	1943 - Los Alamos National Lab opens.
1955	FR	N,N-DMT is identified as one of the psychoactive ingredients of the Anadenanthera peregrina seeds used to make cohoba snuff. This is the first time that N,N-DMT is discovered naturally occuring in a plant or animal.52	1953 - Crick & Watson describe double-helix structure of DNA.
1957	EDP	R. Gordon Wasson publishes an article about psychoactive (psilocybin-containing) mushrooms in Life magazine, the first popular media coverage of their existence.53
1957	EDP	Gordon Alles describes the MDA experience at a conference in Princeton, New Jersey, sponsored by the Josiah Macy, Jr., Foundation.54
1957	EDP	PCP is tested for the first time on 64 human subjects. Worrying side effects such as hallucinations, mania, delirium and disorientation manifest.55
1962	EDP	Wasson first publishes about the psychoactive properties of Salvia divinorum.56
1963	EDP	The first published report of 4-methylaminorex appears in The Journal of Medicinal Chemistry.57
1965	FR	First accounts of the recreational use of Ketamine. Professor Edward Domino describes it as a potent psychedelic drug and coins the term "dissociative anesthetic".58	1968 - Computer mouse first demonstrated by Doug Englebart.
1970	FR	First reported recreational use of MDMA. Six years pass before a scholarly article is published about MDMA's effects.59	1969 - First human walks on the moon.
1975	EDP	First published mention of 2C-B appears in an article about phenethylamines by Alexander Shulgin and Michael Carter.60	1969 - First ARPANET ( internet precursor) trial successful.
1991	EDP	Alexander and Ann Shulgin publish PiHKAL, documenting over 250 phenethylamines, including 2C-T-7 and 2C-T-2.61	1989-1992 - WWW invented, implemented, and launched.