Russia's Winter Olympics is officially underway on the Black Sea coast after a burst of fireworks and a spectacular opening ceremony.
A high-octane show before 40,000 spectators, including leaders of about 40 countries, at the new Fisht Stadium in Sochi signalled the start of the full sporting programme.
Millions more watched on television and via the internet as Russia hosts its first Winter Olympics.
In an early technical glitch, one of the five Olympic rings suspended high above the stage failed to unfurl, meaning that the giant structure could not be illuminated by fireworks as planned.
The show went on with no further interruptions, and cosmonaut Sergei Krikalev hoisted the Russian flag as performers dressed in glowing red, blue and white lights formed a living flag.
The theme of the event was 'Dreams of Russia', with a young girl named Lyubov (love) guiding spectators at the packed arena through thousands of years of Russian history.
Athletes emerged from beneath the stage up a ramp for the traditional parade, and a giant satellite image of each nation taken from space was projected onto the floor.
The honour of lighting the Sochi Olympic flame was given to two triple Olympic champions as Vladislav Tretyak and Irina Rodnina jointly lit the cauldron at Russia's first Winter Games.
Tretyak, 61, who won three Olympic ice hockey golds and a silver and is president of Russia's ice hockey federation, received the torch from figure skater Rodnina and both jogged from the arena to ignite the flame.
Over the next two weeks nearly 3000 athletes will compete in 98 different events.
Some 37,000 security personnel are on high alert at Sochi over threats by Islamist militant groups based in the nearby north Caucasus region to attack the Games.
Separatist guerrillas seeking an independent Islamic state in Chechnya and neighbouring regions of southern Russia have vowed to disrupt the Olympics, which they say are taking place on land seized from Caucasus tribes in the 19th century.
The run-up to the Games has been marked by international criticism of Russia's new "gay propaganda" law.
In his speech, the International Olympic Committee President Thomas Bach called for an inclusive Games. He said it is possible - even as competitors - to live together under one roof in harmony, with tolerance and without any form of discrimination for whatever reason.
As he spoke, gay rights activists said the police detained activists who tried to protest on Moscow's Red Square and in St Petersburg. Russian police did not immediately comment on the reports.
Organisers have also been under fire for the huge costs involved - a record $US50 billion for Winter Games - and unfinished accommodation and amenities.