The tradition of bringing the Olympic flame in a relay from Greece began at the Nazi-tainted 1936 Berlin Games. Under the guidance of Joseph Goebbels, 3,331 runners brought the flame from Olympia.
In Greece, 11 women representing Vestal Virgins will perform a ceremony where the torch is lit using the Sun's rays. It takes place at Olympia, in the Temple of Hera, among the ruins of the Ancient Games.
A great-grandmother, Diana Gould, aged 100, will be the oldest torchbearer in the UK relay. She runs exercise classes in her north London retirement flats and is an inspiration to her neighbours. Her motto is: "Don't think old. Just get on with it."
The youngest torchbearer is Dominic MacGowan, 12, from Birmingham, who won an Outstanding Pupil school award and was also nominated school football captain.
The torch was designed by east Londoners Edward Barber and Jay Osgerby, who won the opportunity through a competitive tender run by the London 2012 Organising Committee and the Design Council.
After it is lit on the 10th, it will be going round Greece and Crete for a week before coming to the UK on Friday 18 May, ahead of the start of the torch relay in Land's End on 19 May.
The torch is made up of an inner and an outer aluminium alloy skin, held in place by a top piece and base, perforated by 8,000 circles.
Representing the inspirational stories of the 8,000 torchbearers carrying the Olympic flame, the circles offer a unique level of transparency. You can see the burner system that keeps the flame alive.
The circles also help to ensure heat is quickly dissipated, without being conducted down the handle.
The torch is being tested in BMW's climatic testing facility in Munich. BMW is a Supporting Partner of the London 2012 Olympic Torch Relay.
It works like a miniature hot air balloon with a vapour off-take system that uses a cylinder full of liquid gas. The top of the liquid is heated by a coil in the burner which is itself heated by the flame, and converts boiling liquid into gas. The canister is filled with two-thirds propane and one-third butane.
The mother flame, in a back-up lantern, can be used to relight a new torch in extreme situations – additional torches will never be more than 30 seconds away.
The triangular-shaped torch was inspired by a series of "threes" found both in the history of the Olympic Games and the vision for the Olympic Movement. There are three Olympic values: respect, excellence and friendship; three words make up the Olympic motto: faster, higher, stronger; and the UK will have hosted the Games on three occasions: in 1908, 1948 and, now, 2012. The vision for the London 2012 Olympic Games is to combine three bodies of work: sport, education and culture.
More than half London 2012's torchbearers are expected to be youngsters, so the torch is designed to be as light as possible.
The special aluminium alloy was developed for the aerospace and automotive industry. It is lightweight but strong, with excellent heat resistance. The 8,000 circles also reduce the weight of the final design, while ensuring strength isn't compromised.
Tecosim, the Basildon-based product engineers; Birmingham-based LPG specialists and manufacturers, Bullfinch; and the Coventry manufacturers Premier Sheet Metal have all taken the design and moved it into mass production.