MOSCOW (AFP) - Ksenia Sobchak, who has surprised Russia by declaring herself a candidate in next year's presidential election, has repeatedly reinvented herself, from privileged party girl to reality TV show host before diving into politics and independent journalism.
Here are five things to know about Sobchak's life and career.
1. Putin a family friend
Sobchak's father Anatoly Sobchak was a liberal politician and the first mayor of Saint Petersburg. His deputy was Vladimir Putin, then fresh out of the KGB, who has acknowledged his importance as a mentor.
Putin stood beside Ksenia and her mother at the graveside after Anatoly Sobchak died of a heart attack in 2000.
Sobchak has made no secret of her close ties to Putin, though the family denies rumours that he is her godfather.
2. Millionaire TV star
Initially compared to Paris Hilton as a tanned blonde socialite who dabbled in showbiz, the 35-year-old Sobchak has built a successful career as a television host and compere.
She started out on Dom-2 (House 2), a low-brow reality show where contestants have to form couples and discuss relationships around a campfire.
She also starred in her own reality show called Blonde in Chocolate, which drew flak for her frequent swearing, as well as hosting Russia's Next Top Model.
Capitalising on her image, she released books of style tips and a perfume called Married to a Millionaire.
In 2011 Forbes magazine estimated her earnings at US$2.8 million (S$4.5 million), and this year it ranked her Russia's 10th best-paid celebrity, with US$2.1 million.
Like many Russian stars, she earns a large chunk of her income by hosting corporate events and weddings.
3. Opposition protester
Sobchak shocked many by appearing at mass protests in 2011 and 2012 against Putin over disputed election results.
Many doubted her sincerity, and when she spoke at a rally for the first time in December 2011, she was greeted by whistles of disapproval.
Her opening line was: "I am Ksenia Sobchak and I have something to lose, but all the same I'm here." She was detained by riot police along with opposition leader Alexei Navalny at a Moscow rally in May 2012 but released without charge.
She also frequently dropped in on a protest camp in a Moscow park the same month, sometimes in full make-up en route to the television studio.
At the time she was dating the opposition politician Ilya Yashin.
4. Her strong online presence
She now has 1.66 million followers on Twitter and 5.2 million on Instagram - which gave the protests a social media megaphone. Shift to opposition media - The protest participation damaged her television career: She quit Dom-2 in 2012 and later that year lost her job at Russia's Next Top Model.
The privately owned MTV Russia also dropped a current affairs debate show after she tried to invite Navalny, who was already persona non grata on state-controlled television.
She now presents an interview show called "Sobchak Live" on the independent TV Rain channel, whose guests have included Navalny and Yashin. She also interviewed former oil tycoon and Kremlin critic Mikhail Khodorkovsky.
5. At home in high society
Sobchak has friends in high places.
She studied at the Moscow State Institute of International Relations, a training ground for diplomats that teems with children of the elite.
Currently she edits the Russian-language version of the French fashion magazine L'Officiel.
As an MC at lavish weddings and birthdays, Sobchak rubs shoulders with the often-secretive ultrarich, including oil and communications tycoons.
Her friends reportedly include fashion designer Ulyana Sergeenko, the model Natalia Vodianova, film director Renata Litvinova and Elena Perminova, the model wife of Alexander Lebedev, whose family controls Britain's Evening Standard newspaper.
In 2013 Sobchak married the film and theatre actor Maxim Vitorgan.
This week, she attended court to support the theatre director Kirill Serebrennikov, who is under house arrest on fraud charges.
She has also conducted public feuds with celebrities including the ballerina Anastasia Volochkova, who was sacked from the Bolshoi in 2003 for being "too fat".