Few doubted who was really in charge and in 2012 Mr Putin returned as president, this time for a term of six years.

If and when he reaches the end of his fourth term in 2024, the 65-year-old will have been in power for nearly a quarter of a century.

That would still fall short of Soviet dictator Joseph Stalin's 31 years in power or, indeed, the reigns of some Russian tsars such as Alexander II (26 years) and Nicholas I (30 years).

Spy turned president

Image copyrightREUTERS

1952: Born 7 October in Leningrad (now St Petersburg), Russia's second city, studies law and joins KGB secret police, serving as spy in communist East Germany

1990s: After serving as top aide to mayor of St Petersburg, enters Boris Yeltsin's Kremlin in 1997, where he is made chief of the FSB (the KGB's successor)

1999: Appointed prime minister, becomes acting president upon Yeltsin's resignation