http://en.wikipedia.org/wiki/Olive_(fruit)

Cultivation

Cultivation of the olive was (and remains) a key characteristic of Mediterranean mixed farming, and played a large part in the economic development of ancient Greece because of the suitability of olive oil as an export crop. For instance Attica, the region of Athens, was a grain importer and olive oil exporter from early historic times. The Athenian pottery industry was stimulated largely by the demand for containers in which to export olive oil.

Soon it was replaced with Spain, that since then and till now has turned into the first world producer of olive oil and olives of the world, being the province of Jaén (Andalusia) the geographical zone of major production in oil and the province of Seville (Andalusia) in olive.

In modern times the olive has been spread widely around the world; and, though the Mediterranean lands that were its ancient home remain the main source of the oil, the tree is now cultivated successfully in many regions unknown to its early distributors. Protected by high brick walls, a fruiting olive tree is in the Chelsea Physic Garden, London. Soon after the discovery of the Americas it was taken there by the Spanish settlers. In Chile it flourishes as luxuriantly as in its native land, the trunk sometimes attaining a large girth, while oil of fair quality is yielded by the fruit. To Peru it was carried at a later date and now has flourished very successfully. It was introduced into Mexico by the Jesuit missionaries of the 17th century, and to Upper California (where it stagnated later). Olive cultivation has also been attempted in the south-eastern states, especially in South Carolina, Florida and Mississippi. In the eastern hemisphere the olive has been established in many inland districts which would have been anciently considered ill-adapted for it. It was known at a comparatively early period of history in Armenia and Persia, and many olive-groves now exist in Upper Egypt. The tree has been introduced into Chinese agriculture, and has become an important addition to Australia's farmers, and there are probably few coast districts there where the tree would not flourish. In Queensland the olive has found a climate specially suitable; and in South Australia, near Adelaide. It has likewise been successfully introduced into some parts of South Africa and New Zealand.


Packaged olives, sold as an Italian snack foodA pleasing substitute for the butter and animal fats consumed by people to the north, the olive, among the southern nations of antiquity, became an emblem not only of peace but of national wealth and domestic plenty; the branches borne in the Panathenaea, the wild olive spray of the Olympic victor, the olive crown of the Roman conqueror at ovation, and those of the equites at their imperial review were symbols of peace that, in a barbarous age, could be secured by victory alone. Among the Greeks the oil was valued as an important article of diet, as well as for its external use. The Roman people employed it widely in food and cookery--the wealthy as an indispensable adjunct to grooming; and in the luxurious days of the later empire it was said that long and pleasant life depended on two fluids: wine within and oil without. Pliny describes fifteen varieties of olive cultivated in his day, the Licinian being most esteemed, and the oil obtained from Venafrum in Campania, the finest known to Roman connoisseurs. The produce of Istria and Baetica was then regarded as second only to that of the Italian peninsula.

Gourmets from the Roman empire to the present day have valued the unripe fruit, steeped in brine, as challenging to the palate. Pickled olives, retaining their characteristic flavor, have been found among the buried stores of Pompeii. Note also that the green olive and black olive are from the same plant; green olives are pickled before being ripened, black olives after.

The bitter juice deposited during pressing of the oil (called amurca), and the astringent leaves of the tree have many virtues attributed to them by ancient authors. The oil of the bitter wild olive was employed by Roman physicians in medicine, but does not appear ever to have had a culinary use.

The olive is used in different culinary disciplines: in cocktails it is an essential adjunct of the martini; in sausages, it may be used in mortadella and so on. It is commonly used in breads as well.