Archaeological researchers have found that the Yamnaya people, a group of nomads who entered Europe during the Bronze Age, were the first pot dealers to establish a transcontinental cannabis trade, New Scientist reports.

In a study published in the journal Vegetation History and Archaeobotany, experts from the German Archaeological institute and the Free University of Berlin based their discovery on evidence of cannabis pollen, fruits, and fibers that were found during archaeological sites throughout Europe and East Asia.

Researchers say that cannabis was used in the region as a source of food and medicine, as well as textiles made from the plant's fiber. Marijuana's myriad uses were the impetus for making it a cash crop.

"Cannabis's multiple usability might have made it an ideal candidate for being a 'cash crop before cash', a plant that is cultivated primarily for exchange purpose," Tengwen Long, a paleontologist at German Archaeological Institute and the Free University of Berlin, told Live Science.