As Russia prepares for presidential elections on 14 March, BBC Monitoring profiles the five challengers to the incumbent, Vladimir Putin.
A sixth contestant, Ivan Rybkin, dropped out of the race on 5 March, a month after he went missing in mysterious circumstances then abruptly reappeared.
Glazyev: seen as 'biggest threat'
From the outset of the election campaign controversy has surrounded the economist and ex-Communist Sergei Glazyev.
The 43-year-old, who co-chaired the Motherland bloc to unexpected success in the 2003 parliamentary elections, is seen by many as the biggest threat to Vladimir Putin.
But this may have cost Mr Glazyev the backing he needs. His party colleagues have made clear their support for Mr Putin, forcing Mr Glazyev to set up his own rival group, also called Motherland.
Mr Glazyev's campaign has presented him as a fierce critic of recent economic reforms. He argues that successive governments have ignored social justice and he has promised to improve welfare.
Criticism of government policy also marked his four years as a Communist MP, when he attacked what he calls the "criminal privatisation" of Russia's resources.
Mr Glazyev also has his own experience of power. He served as foreign trade minister in the early 1990s, before entering parliament in 1994.
Khakamada: second woman to run
Of all the contestants it is Irina Khakamada who has emerged as the most outspoken opponent of Vladimir Putin.
This has meant she no longer enjoys the backing of her party, the centre-right Union of Right Forces. But she remains undeterred.
"I am not afraid of the terrorists in power," she told the Kommersant daily. "Our children must grow up as free people. Dictatorship will not be accepted."
Ms Khakamada was born in 1955, the daughter of a Japanese Communist who took Soviet citizenship . An economics graduate, she was a consultant to the Russian stock and commodities exchange in the early 1990s.
In her eight years in parliament, from 1995, she established herself as a leading economic liberal. But she failed to retain her seat in the last elections.
She has portrayed herself as bridging the gap between the older and younger generations. And the fact that she is only the second woman to run for president may pick her up some votes.
Kharitonov: 'surprise' choice
Nikolai Kharitonov became the Communist Party's surprise candidate when chosen in late December.
Most observers expected party leader Gennady Zyuganov to stand for a third time. And Mr Kharitonov, 55, is not even a party member.
He is, however, a founder member of the People's Patriotic Union, the left-wing movement founded by Mr Zyuganov in 1996 to unite opponents of reform. Mr Kharitonov took his Agrarian Party of Russia into the union at its inception.
"I am not a member of the Communist Party, but when it comes to strength of ideological convictions, mine may be stronger than some of theirs," Mr Kharitonov told Russian TV.
Once a colonel in the KGB, he is also known for backing plans to return a statue of Felix Dzerzhinsky, founder of the secret police, to its former site outside Moscow's old KGB headquarters.
Malyshkin: standing in for Zhirinovsky
Some say it is a measure of President Putin's huge popular support that nationalist politician Vladimir Zhirinovsky has chosen not to run against him.
Instead, Mr Zhirinovsky's Liberal Democratic Party (LDPR) turned to Oleg Malyshkin, one of his lieutenants.
Mr Malyshkin, 52, has a lower profile than most of his rivals. A mining engineer by trade, he has been an LDPR member since 1991, but only entered parliament in 2003.
So far, relatively little is known about his policies and views. He has, however, cultivated something of a "man of the people" image.
"I started work at 16... and I started at the pit face. For five years, I hacked coal down the mine," he told reporters.
Mr Zhirinovsky has sought to promote this image. "We're not talking about country houses, oligarchs or Mercedes," he has said. "He is an educated man, however, who knows the needs of ordinary people."
Yet Mr Malyshkin is on record as saying he would stand down in favour of Mr Zhirinovsky if he were to win.
Mironov: close to Putin
Sergei Mironov's decision to stand has been a source of bewilderment among observers.
As speaker of the Federation Council, the upper house of parliament, the 51-year-old has consistently backed President Putin.
So why stand against him?
Indeed Mr Mironov has been quoted as saying: "We all want Vladimir Putin to be the next president."
Then even more confusingly he has said: "I sincerely believe election opponents can both be - and not be - adversaries. I am not an adversary of Putin."
Like the president, Mr Mironov comes from St Petersburg, and in 2000 he served as Mr Putin's deputy campaign manager in the 2000 presidential elections.
His campaign website says he aims to "make people's lives better" and to ensure that living standards "reflect the country's natural, intellectual and spiritual wealth".
He has promised to fight corruption and tackle Russia's many environmental problems.
BBC Monitoring, based in Caversham in southern England, selects and translates information from radio, television, press, news agencies and the Internet from 150 countries in more than 70 languages.