Wrestling is widely recognised as the oldest competitive sport in the world. Cave drawings have been found from the Sumero-Akkadian civilisation depicting wrestlers from 3000BC and similar wall paintings from ancient Egyptian civilisations date from 2400BC. Much later, the Greeks introduced wrestling to the ancient Olympics in 708BC.
Greco-Roman wrestling, deemed a pure reincarnation of ancient Greek and Roman wrestling, was a key part of the first modern Olympics in Athens in 1896 and has more-or-less remained part of the Games since, being absent only in Paris in 1900. In this form, wrestlers can use only their arms and upper bodies to attack and can hold only those same parts of their opponents.
A second style of wrestling, known commonly as "catch as catch can", had by then become a popular professional entertainment in Britain and the United States, and in 1904 was introduced to the Olympics under the guise of freestyle wrestling. These wrestlers can use their legs for tripping, lifting and pushing and can hold opponents above or below the waist.
Women's events were added to the Olympic programme in Athens in 2004, where women from 21 nations competed in four freestyle weight classes.
There are 18 events in Olympic wrestling. Men contest Greco-Roman and freestyle wrestling in seven bodyweight categories: under 55 kilograms, 55-60kg, 60-66kg, 66-74kg, 74-84kg, 84-96kg and 96-120kg. Women's freestyle wrestling was introduced in 2004 and there are four bodyweight categories: under 48kg, 48-55kg, 55-63kg and 63-72kg.
Wrestling matches take place on a specially marked mat, which looks like a target.
There is a centre spot and a red one-metre wide band forming a circle of nine metres and is and is surrounded by a 1.5m border. Colours mark the competition zones, and wrestlers wear the corresponding blue or red singlet.
In Greco-Roman style, wrestlers can only attack and hold using their arms and upper body, in freestyle they can use their legs as well.
Prior to competition, wrestlers are weighed. Matches last five minutes unless either wrestler scores a "fall" or technical fall. A fall happens when a wrestler pins his opponent down so that both his shoulders come into contact with the mat. When this happens, the referee signals that the bout is over.
To win at the end of five minutes, a wrestler must have scored a minimum of three technical points. If neither wrestler has scored three points, then the match goes into overtime until the next point is scored, for a maximum of three minutes. If no point is scored in three minutes then judges decide. If a wrestler scores ten points in a bout he is declared winner.
Wrestling is hugely popular in Eastern Europe, Scandanavia and the Middle East. Probably the best known name is Siberian-born Aleksandr Karelin, who was one of Russia's leading performers between 1988 and 2000. A super heavyweight Greco-Roman wrestler, Karelin made his Olympic debut in Seoul and comfortably defeated his first four opponents. He trailed Bulgarian Rangel Gerovski 3-0 in the final with only 30 seconds left, but used a reverse body lift to score a five-point takedown and won gold.
Karelin was undefeated between then and the Barcelona Olympics, and eased his way to a second gold medal, with only one of his opponents lasting until the time limit. In Atlanta, Karelin became the first wrestler to win the same weight division three times and outscored his five opponents 25-0 in the process. The one blemish on his Olympic career came in the final of the Sydney Games in 2000, when a rare lapse of concentration cost him his 13-year unbeaten record. Karelin lost 1-0 to the USA's Rulon Gardner and had to settle for silver.
In 2001, Karelin, who also won nine World Championships, received the Olympic Order, the highest award of the Olympic Movement, from the then President of the International Olympic Committee Juan Antonio Samaranch.
Freestyle wrestling has its roots in Lancashire, it is believed. "Catch-as-catch-can" wrestling gained great popularity in fairs and festivals during the 19th century in the area. Both contestants started out standing and then a wrestler sought to hold his opponent's shoulder to the ground (known as a fall). If no fall was scored, both wrestlers continued grappling on the ground, and almost all holds and techniques were allowable.
A handkerchief, also called a bloodrag is carried in the singlet. In the event of bleeding, the wrestler will remove the cloth from his singlet and attempt to stop the bleeding or clean up any bodily fluids that may have gotten onto the mat.