The Olympic Flame was handed over to London on Thursday.
David Beckham was at the ancient Panathenaic Stadium to help collect the flame and bring it back home.
The historic event took place in a rain-hit sundown ceremony at the stadium in Athens, venue of the first modern Olympics in 1896.
The flame has been handed over to London to host the Games for the third time since the birth of the Olympics - in 1908, 1948 and now 2012. No other city has staged the Games three times.
Despite the buzz triggered by the last-minute news that the former England football capatain was flying in specially to be part of the ancient ceremony, the more formal duties came down to the Princess Royal as leader of the British delegation to Athens.
Both she and Karolos Papoulias, the Hellenic Republic president, sat in ancient thrones that are part of the stadium during the hour-long ceremony.
The flame was handed to the Princess, who was watched closely by other members of the official delegation including London 2012 chairman Lord Coe, Olympics minister Hugh Robertson, London mayor Boris Johnson, Beckham and five British sporting teenagers.
Each member of the British VIP delegation sheltered under blue umbrellas as they walked through the centre of the stadium to their front-row seats.
Everyone from the Princess Royal to Mr Robertson was named over the loudspeakers and greeted by cheers from the crowd.
There was also a chuckle from Britons in the crowd as the announcer twice insisted on introducing Beckham as Sir David Beckham.
The youngsters were picked by London 2012 for displaying Olympic values. During the ceremony they exchanged symbolic olive branches to the tune of John Lennon's Imagine.
The five, who come from different national regions, are from schools and colleges which are part of London 2012's Get Set education network and school linking programmes run by the British Council.
A smiling Sakinah Muhammad, 15, from Clapton Girls' Academy in Hackney, east London, who is one of the British youngsters, said: "When I first found out I was in shock.
"I did not believe what they were telling me and that I was going to be something that is such a big deal. I am so excited that I am part of it."
The other British teenagers included Scottish rugby player Dennis Coles, 17, from Doon Academy, Dalmellington, East Ayrshire; hockey player Chloe Brown, 18, from South Eastern Regional College in Bangor, Northern Ireland; and Swansea Harriers athlete and Mumbles Rangers FC player Sean White, 17, from Bishop Vaughan Catholic School in Swansea.
There was also Falmouth Ladies hockey player Georgia Higgs from Helston Community College and school sports ambassador who represents Cornwall, where the flame will touch down ahead of the 70-day torch relay to the start of London 2012.
The Olympic Flame has been taken on a relay around the Greek mainland and islands since it was lit by the rays of the sun in ancient Olympia last week.
It has visited Crete, Piraeus, Thessalonica, Xanthi and Larissa, among other places.
The torchbearers have been taking it from Olympia to the Panathenaic Stadium. The Olympic flame was "laid to rest" at the Acropolis overnight before being taken on the eighth and final day of its Greek relay -taking it to the Acropolis Museum, the centre of Athens, Zappeio and to the handover ceremony.
A trio of world champions brought the flame safely to the stadium. It arrived in the hands of rower Christina Giazitzidou and was carried by gymnast Vasilis Tsolakidis and rower Alexandra Tsiavou.
Chinese gymnast Li Ning, who lit the cauldron at the opening ceremony for the 2008 Beijing Games, and Greek weightlifter Pyrros Dimas were the last torchbearers in Greece.
In a new symbolic move by the Hellenic Olympic Committee, they were picked to represent a link between the last Olympics in Beijing, with Greece as the birthplace of the institution and also the next Games in London 2012.
Li Ning is the 14-time world champion who won six medals at the 1984 Olympics including three golds, while Pyrros Dimas is something of a modern-day Greek sporting hero.
He won Greece's first Olympic weightlifting gold since 1904 when he was a 20-year-old competing in the 82.5kg weight class at the Barcelona 1992 Games.
He was on his way to winning three Olympic gold medals during his career, which he ended with a bronze in front of his home crowd at the 2004 Athens Games.
The image of him symbolically leaving his shoes on the platform to a standing ovation is one of the most memorable of the Games.
The ceremony also included priestesses in a performance choreographed by Artemis Ignatiou.
It was to wish good luck to the Greek team that will compete in London, complete with the slogan "Greece you can do it".
The British delegates fly back tomorrow evening, landing at RNAS Culdrose in Cornwall, where they will attend a special ceremony welcoming the flame.
A 70-day relay, involving 8,000 torchbearers covering 8,000 miles, will then take the flame to east London's Olympic Stadium and the opening of the Games on July 27.