In ancient times, the Silphion plant was only grown alons the Libyan coast and its export to the other parts of the Asia Minor and of the Mediterranean was the main source of Kyrene's wealth. According to tablets found at the Knossos by Sir A. Ewans, the plant was already known long before 7th century B.C.; its is mentioned that the Therans went to Kyrene probably to obtain the Silphion plant.Silphion was occasionally used as a symbol on the Archaic and Classical coins of Kyrene. This depiction of the plant disappears by the Hellenistic period. Nowadays, Silphion plant is used for cooking and as a medicine to prevent cold. However, on the Kyrenean coins, Silphion is depicted with an unclothed women sitting near the plant or with a women holding her hand on her sexual organ. Both of these representations indicates that the plant is related particularly with the women. Another evidence are the terracotta female figurines holding in one hand a Silphion plant and in the other a sickle. As we know both from written sources as well as from archaeological finds, birth control practice was known through antiquity.The colonisation movements had resulted an increase in population. The use of Silphion as a means for birth control begun probably at this time and continued up to the Hellenistic period.By the beginning of the 20th century, historians have accepted that the birth control was already known in ancient times and the Silphion was used instead of superstitious methods as spells. The practice of birth control disappears under monotheic religion during the Middle Ages, only to reappeare at present with the uncontrolled increase in the population.