Approximately 7,500 years ago agricultural communities began to develop along the basin of the Danube River. Within less than 200 years they had spread to Belgium and northern France in the west and Ukraine in the east. Where their ancestors had foraged and hunted for a living, these people (called linearbandkeramik or LBK culture for their distinctive pottery) worked the land for their food. They took cues – and seeds – from the Near East, where farming had been taking place for millennia. Among the charred remains of their fires archaeologists have found traces of emmer and einkorn wheat, linseed (flax), lentils and peas, crops which originated in modern-day Turkey, Syria, Israel and Iran. But amidst all those eastern seeds there was one other non-native plant that came not from the east but from the southwest – Papaver somniferum, otherwise known as the opium poppy.
Today most modern-day botanists believe P. somniferum descends from Papaver setigerum, a wild poppy growing in the western Mediterranean. P. setigerum is found in Italy, northern Africa, eastern Spain, the Mediterranean coast of France, and the Canary Islands. P. setigerum is slightly smaller than P. somniferum: its leaves are thinner, with long jagged teeth tipped with a bristle that is not found on P. somniferum leaves: they also lack P. somniferum's waxy coating. Like its domesticated cousin, P. setigerum contains morphine alkaloids: indeed, the two poppies are so similar that the wild poppy is commonly called Papaver somniferum ssp. Setigerum or even Papaver somniferum var. setigerum.
It has been suggested that poppies were introduced to LBK agriculture via trade with the La Hoguette culture, a group known primarily by its distinctive bone-tempered pottery. The La Hoguette culture is believed to have originated in southern and southwestern France: they descended from an earlier "Impressed Ware" culture which resided on the shores of the Mediterranean. La Hoguette and LBK pottery has been found together at many sites east and west of the Rhine, suggesting there was contact and trade between the two cultures.
From there, poppies continued on their journey northward. A dig at Raunds, a site in rural Northamptonshire, England, discovered eight opium poppy seeds dated from the early Neolithic period (5,800 – 5,600 years BP). While opium poppies can grow as weeds, the lack of other weeds in the ditch, as well as the absence of cereal remains, suggest this plant may have been a crop in its own right. While Neolithic civilization has traditionally been envisioned as scattered collections of hunter-gatherers who supplemented their foraging with primitive agriculture, the Raunds poppy seeds reveal trade routes between Britain and the Continent. They also suggest that the people of Raunds held poppies in high regard – high enough, at least, to carry seeds across the English Channel, then haul them into the East Midlands and plant them.
At Cuevo de los Murciélagos ("Cave of the Bats," a Neolithic burial site located in Albuñol, Granada in southern Spain), we find still more evidence of poppy usage. Thanks to the cave's arid conditions, the round woven grass bags which were buried with the dead have been preserved, along with their contents – large numbers of poppy capsules which have been shown by carbon dating to be over 6,000 years old. Given the somnolence caused by ingestion of poppies, it seems clear that even at this early date they were associated with death and, presumably, with shamanic journeying.
Excavations at Egolzwil, an archaeological site located in Switzerland's Lucerne canton, have revealed signs of poppy cultivation dating back over 6,000 years, including poppy seed cakes and poppy heads. These may have been used to feed their cattle in emergencies (cattle generally dislike foraging on bitter-tasting poppies and will only eat them if no better food is available) but these farmers would certainly have known that poppies can produce intoxication and even death in cattle if too many are given. Yet evidence suggests that poppies were the most common crop at Egolzwil, more common than club wheat, barley or flax.
Even earlier evidence of opium poppy use comes from recent underwater archaeological work at La Marmotta, a site in Lake Bracciano, Italy (northwest of Rome). La Marmotta was occupied by a Neolithic farming community for about 500 years before it was abandoned, then submerged by water some 7,700 years ago. Based on the sophisticated artifacts found at the La Marmotta site – and the paucity of evidence for any other contemporaneous cities or villages in the area – archaeologists believe this was a colony from another civilization in Greece or the Near East. And given the model boats (along with a well-preserved longboat found buried in the mud), it seems likely that there was considerable water traffic between the La Marmotta colony and traders from other civilizations."This was not an ordinary village," says Maria Antonietta Fugazzola Delpino, director of the La Marmotta expedition. "The people were in touch with other communities in the Mediterranean. We picture it as a kind of highway—there were many ships coming and going." Organic remains preserved beneath three meters of limestone included poppy seeds, presumably cultivated for food, oil, medicine, and possibly for religious use.
 Leendert P. Louwe Kooijmans. "The Mesolithic/Neolithic Transformation in the Lower Rhine Basin" in Case Studies in European Prehistory, (Peter I. Bogucki, Editor). Boca Raton, CRC Press, 1993. 130.
 C.C. Bakels. "Abstract: Papaver somniferum culture in prehistory and early history" (2004) at Program Symposium: Plants in Health and Culture. www.plantsinhealthandculture.nl/plantsinhealthandculture/Abstracts/AbstractBakels.html. Accessed January 13, 2009.
 Gill Campbell and Mark Robinson (with Polydora Baker, Simon Davis and Sebastian Payne). "Environment and Land Use in the Valley Bottom" at English Heritage. www.english-heritage.org.uk/upload/pdf/018-036_Chapter2_FINAL.pdf. Accessed January 14, 2009.
 Graeme Baker. Prehistoric Farming in Europe. Cambridge University Press, 1985. 123.
 Robert Kunzig. "La Marmotta." Discover, November 1, 2002. http://discovermagazine.com/2002/nov/cover. Accessed January 13, 2009.