Vladimir Putin's inner circle: Who's who, and how are they connected?

Updated 7:43 AM ET, Tue March 28, 2017

Moscow (CNN)He's one of the most powerful men in the world. Born in St Petersburg in 1952, Vladimir Putin worked as a KGB spy in East Germany before going into politics -- working his way up from the mayor's office in St Petersburg to the top job of President.

Estimates of his personal wealth vary wildly -- officially he owns a small apartment, garage and a few cars, but at least one estimate puts his personal wealth at up to $200 billion.
According to Putin's spokesperson, Dmitry Peskov, suggestions of vast wealth are a "perverted commenting of reality."
The Russian President does, however, have many wealthy friends who are alleged to have benefited from their links to him.
These are the people who make up his inner circle.

Igor Sechin

Russia's President Vladimir Putin talks to Rosneft President Igor Sechin in Moscow in 2013.
As the head of one of the world's largest oil companies, Rosneft, Igor Sechin is one of the most powerful men in Russia.
Like Putin, Sechin has come a long way since the early 1990s when the two men worked together in the St Petersburg mayor's office. After he followed Putin to Moscow, Sechin continued to work closely with his old boss -- both as his presidential aide and then as deputy prime minister.
In 2014, after Russia annexed Crimea from Ukraine, and after his stint in Putin's administration, Sechin was put under sanctions by the US treasury which said he had "shown utter loyalty to Vladimir Putin - a key component to his current standing."

Gennady Timchenko

Billionaire Gennady Timchenko, taking part in the St Petersburg International Economic Forum 2014.
With a fortune of about $15.5bn, Gennady Timchenko is ranked 85 on Forbes' billionaires list.
Although he has a luxurious lifestyle now -- and played hockey with Putin -- he has not always been so wealthy. Timchenko comes from humble beginnings -- his wife Elena said the couple used to live in a communal apartment in St Petersburg with "bedbugs and the smell of borscht soup in the kitchen." Their elder daughter, she said, first slept in a suitcase in their room.
Timchenko says he has known Putin for more than 20 years but says "when I am asked questions about our friendship, I always say, please turn to Vladimir Vladimirovich. If I call myself a friend of his, it wouldn't look appropriate."
Timchenko is one of the founders of Gunvor -- a global company that trades in oil and energy markets.
Like other members of Putin's inner circle, Timchenko has been sanctioned, forcing him to ground his private jet in Moscow after Gulfstream refused to service the aircraft.
The US Treasury has claimed that "Timchenko's activities in the energy sector have been directly linked to Putin. Putin has investments in Gunvor and may have access to Gunvor funds." Gunvor has denied this, saying "President Putin has not and never has had any ownership, beneficial or otherwise in Gunvor."
After being slapped with sanctions, Timchenko is reported to have said "you have to answer for everything, even your friendship with the president."
As a sign of Timchenko's closeness to Putin, he was gifted a puppy by Putin from his beloved dog Connie, according to Russian media reports.

Dmitry Medvedev

Russian Prime Minister Dmitry Medvedev during a TV interview on December 10, 2014.
Russia's prime minister, Dmitry Medvedev, and Putin go a long way back. Both of them are from St Petersburg and worked for mayor Anatoly Sobchak in the early 1990s.
After Putin moved to Moscow and became Prime Minister, Medvedev followed him and was appointed deputy chief of staff to the President.
In 2008 he and Putin implemented a controversial power sharing agreement. At that time, Putin had already served two terms as president and was constitutionally barred from serving a third consecutive term. Medvedev became president and Putin became prime minister. Four years later, they swapped back again.
The two men are close; in 2015 they were shown in a video working out in Putin's gym in Sochi and barbecuing their breakfast together.

Nikolai and Kirill Shamalov

Kirill Shamalov is reported to be married to Vladimir Putin's daughter Katerina.
Vladimir Putin's daughter Katerina -- who is said to be an academic and an acrobatic rock 'n' roll dancer -- is reportedly married to Kirill Shamalov. He is the son of Nikolai Shamalov, an old friend of Putin's from St Petersburg.
Nikolai Shamalov helped co-found the Ozero cooperative -- an elite dacha community built near St Petersburg in the 1990s, of which Putin is also member.
Nikolai's son Kirill is said to be one of Russia's youngest billionaires with a stake in Sibur, a Russian petrochemical processor.
Nikolai Shamalov has been sanctioned by the European Union for being a "long-time acquaintance" of Putin and for benefiting from "his links with Russian decision-makers."

Sergei Roldugin