Olive trees (Olea europaea L.) are among the oldest historically important fruit trees. References to olives within the western civilized world date back to Biblical and Roman times and to Greek mythology. Extra virgin olive oil proved itself indispensable in the ancient world, and was called “liquid gold” by Homer and “the great healer” by Hippocrates, placing olive oil at the top of the food and medicine list (Clodoveo et al., 2014). Kings were anointed with olive oil as a sign that they were chosen by God to rule (1 Samuel 16:1). Olive oil was considered by the Egyptian and Minoan civilizations to be of vital importance, and it was sometimes used as a form of currency (Arte Legno, 2016). The oil, fruit, and leaves of the olive tree have an ancient history of nutritional, medicinal, and traditional uses. Olives and olive leaves are the first botanicals prominently noted in the Bible, in Ezekiel 47:12, “The fruit thereof shall be for meat, and the leaf thereof for medicine” – thus its nickname, “Tree of Life.” The Spartans rubbed olive oil on their bodies as a moisturizer and to emphasize their physique, while Greek athletes received olive-oil massages. Early Roman emperors gave olive oil as gifts during celebrations. The Romans developed the screw press to extract the oil, a technology that is still used today. In the Eastern world, the first Japanese known to have eaten olive fruits was Toyotomi Hideyoshi, an Imperial Regent of Japan. He received a barrel of salted olives from Spanish King Felipe II in 1594. In the early 1860s, the shogun’s physician, Hayashi Doukai, who studied Dutch medicine in Nagasaki, developed the first trial orchard in Japan to produce olive oil for medical use (Takeuchi and Shibata, 2012).

Olive tree culture was an important agricultural activity and a symbol of wealth and security in ancient civilizations (Rick, 2016). “The olive tree is surely the richest gift of heaven” said Thomas Jefferson (Firenze, 2011).