The principal diet consisted of grains, peas, watermelon, squash, grapes, figs, eggplants and olives in ancient Greece, 2,000 years B.C.

The Cretans celebrated the olive harvest with a great feast.

In Homeric poems, olive oil was used exclusively for cleanliness and hygiene. The olive tree was considered a rare and exotic plant.

The Hebrews, after their Exodus from Egypt, also cultivated the olive tree and produced olive oil.

The hero Aristaeus, is worshipped as the first to obtain oil from the pressing of the olives.

Latona gave birth to the twins Diana and Apollo under the branches of an olive tree, which later became a sacred object.

Hercules brought the seed of an olive tree from the land of the Hyperboreans, the present Crimea, to plant it at the foot of Mount Olympus.

In the Judeo-Christian tradition, the olive tree also marks the beginning of history. It is an olive branch that the dove brings Noah after the Great Flood.

The olive tree - along with wine - was the greatest source of wealth from trade in the ancient world.

In Ancient Rome, olive oil was classified into categories – from oleum ex albis ulivis (made from green olives and considered the best) to cibarium (rotten olives), which was for the consumption of slaves.

Populations conquered by the Romans were ordered to pay taxes in the form of olive oil. Under Roman rule, the Mediterranean region was divided according to olive oil markets.

The Romans established procedures to govern the supply, distribution, and trade of olive oil. Seafaring vessels ensured its speedy transportation.

The olive tree was the first type of tree to be cultivated by the people living along the Mediterranean basin.

The Code of Hammurabi (2,000 B.C.) governed the olive tree trade and prohibited, under penalty of death, pruning an olive tree more than two feet per year.

Before the olive tree was cultivated in the Iberian Peninsula, Phoenicians supplied the peoples of modern day Spain with olive oil in exchange for silver bars.

Today the olive tree is cultivated beyond the Mediterranean, in places such as California, Texas, Argentina, Australia, South Africa and China.

The olive tree is a very hardy evergreen and can be found growing and thriving in conditions which would kill other fruit trees.

When the olive tree is in bloom, it is covered with groups of small, white, sweet-smelling flowers. The trees blossom from April until June.

The olives ripen and can be harvested from late October to January, depending on the region. In regions at risk of an early frost that could damage the fruit, the harvest is early.

Olives are comprised of three components: oil (15-25%); solids consisting mainly of cellulose, proteins and sugars (25-35%); and water.

The best way to harvest the ripe olives is to pick them one by one and gather them in a woven, natural fibre basket to protect the olives from bruising.

During harvesting and transporting, it is very important that the olives are not bruised. For this reason, the olives are gathered in low baskets or crates, and not in sacks.

Once the harvested olives reach the olive mill, they are removed from the baskets and spread out in wooden flats which are stacked, one on top of the other, leaving enough space in between to allow air to circulate.

The olives are then passed over a vibrating belt to separate them from any remaining leaves and twigs.

Olives can become dirty and need to be rinsed before crushing, particularly when harvested from the ground.

After the olives have been rinsed, they are ready to be crushed, and are transported to the mill.

It is important that there is no delay in extracting the oil from the olives, as the passage of time will allow the fruit to become oxidized, and thereby destroy the quality of the oil.

Traditionally, heavy granite wheels were used to crush the olives--along with the pits--into a coarse paste called "must" or, in Italian, "musto."

Today, many olive mills are replacing stone wheels with more modern crushing machinery, equipped with hammer-like arms, which gently break up the olives.

The new method is faster, and the stainless steel machines make cleaning much easier. With this newer method, the oil is separated from the must without an actual "pressing".

In a traditional pressing, the must is spread on cocoa fiber mats and stacked in a mechanical press. As pressure is applied, oil and water seep from the mats, and is collected in vats below the press.

Traditionally, the separation of the oil from the water was achieved by letting the oil decant naturally. Oil, being lighter than water, slowly rises to the top and could be removed with a flat copper ladle.

Today, the oil produced from the traditional pressing method is typically separated from the water by centrifuges which are much faster and more efficient.

The oil that results, called "virgin" because it is uncontaminated and unprocessed, can be labelled as "extra" virgin if it contains less than 1% free oleic acid.

Air, heat and light are the natural enemies of olive oil. Before bottling, extra virgin oil is stored in a cool, dark and dry area, at a temperature ranging between 13°-15° C (55°-59°F).

Similarly, at home, olive oil should be stored in a cool--but not cold--dark place in a tightly covered container. Stored properly, olive oil has a shelf life of 18 months or more.

"Must" or "novello" extra virgin olive oil: Extra virgin olive oil ranging in age from freshly pressed until about four months, with a characteristic deep green color and strong flavor that tickles the throat.

"Robust" or "olio ferro" extra virgin olive oil is extra virgin olive oil between 5 and 8 months, exhibiting a transparent dark green color with golden highlights and a fruity flavour and aroma.

"Young" extra virgin olive oil: The most sought after extra virgin olive oil, with an age ranging between 8 and 12 months. The colour has changed to a golden green with a smooth olive flavour and aroma.

"Old" extra virgin olive oil refers to aged extra virgin olive oil. However, by the third year, it is likely that the oil will be old and inedible even if it has been properly stored.

Industrially produced, flavourless and inexpensive vegetables oils are common nowadays. However, extra virgin olive oil is by far the best when it comes to taste and fragrance. It is also very easy to digest.

Extra virgin olive oil is a completely natural product, high in monounsaturated fat-- the "good fat" -- and is a source of antioxidants, making it a healthier alternative to butter, both as a condiment and in cooking.

Nutritionists the world over are now recommending that consumers replace the less healthy fats in their diets with extra virgin olive oil as part of a diet designed to help people live healthier lives.

Other vegetable oils and margarine are often highly processed foods that can't compare to the goodness of extra virgin olive oil.