The Olympic Flame is to be lit on Thursday at a ceremony which signals to the world that the countdown to the London 2012 Games has begun.
The ceremony will take place in Olympia, Greece, where the ancient Olympic Games took place and it will be filled with history, ritual and symbolism.
The flame itself is seen as representing positive values and is lit using the sun's rays is so that its purity is guaranteed. Ritual states that this is the only way the Olympic Flame can be lit.
A team of the world's top Olympic and sports executives, including International Olympic Committee president Jacques Rogge, Hellenic Olympic Committee president Spyros Capralos and London 2012 chairman Lord Coe, will gather at the Ancient Olympia Stadium for the lighting of the sacred flame.
In front of the ancient ruins of the Temple of Hera, an actress playing the role of a high priestess will light the flame by the rays of the sun in a parabolic mirror.
The flame is placed in an urn and taken to the ancient stadium where Spyros Gianniotis, 32, the world champion 10km swimmer, will be waiting to begin the first leg of the torch relay across Greece. The Greek swimmer was born in Liverpool on February 19 1980 to a Greek father and a British mother.
He passes it on to 19-year-old Alex Loukos was one of the 30 East End schoolchildren who travelled to Singapore in 2005 as part of the closing presentations for London's bid. Mr Loukos, a keen boxer, has been training for his role as the second torchbearer by running around the streets near his East Ham home.
The flame will visit Crete, Piraeus, Thessalonica, Xanthi and Larissa, among other places, in a relay around the Greek mainland and islands. The torchbearers are taking it from Ancient Olympia to the Panathenaic Stadium in Athens, where the first modern Olympics were held in 1896, for the handover to London on May 17.
After the May 17 ceremony, the flame is then flown to the UK, landing at RNAS Culdrose, near Helston, Cornwall, on May 18 for a 70-day relay around Britain. Starting at Land's End, this will see 8,000 torchbearers carrying it from May 19 to the lighting of the cauldron at the opening ceremony at the Olympic Stadium in Stratford, east London.
The London 2012 Olympics begin on July 27.