Mr Putin, seen here at the Grand Kremlin Palace in Moscow in 2019, is a former KGB officer
Through the ages, Russian rulers have gained power in different ways.
For tsars it was by birth; Vladimir Lenin through revolution; general secretaries of the Soviet Communist Party by climbing up the party ladder to the politburo and awaiting their turn for the top job.
But 20 years ago, Vladimir Putin was handed power on a Kremlin plate. The former officer of the KGB - the Soviet security service - was handpicked by President Boris Yeltsin and his inner circle to lead Russia into the 21st Century.
But why Mr Putin?
The 'brilliant deputy'
Valentin Yumashev played a key role in Vladimir Putin becoming president of Russia. The former journalist turned Kremlin official rarely gives interviews, but he agreed to meet me and tell his story.
Mr Yumashev was one of Boris Yeltsin's most trusted aides - he went on to marry Mr Yeltsin's daughter, Tatyana. As Mr Yeltsin's chief of staff, in 1997 he gave Mr Putin his first job in the Kremlin.
"Yeltsin's outgoing administration chief, Anatoly Chubais, told me he knew a strong manager who'd make a good deputy for me," Mr Yumashev recalls.
"He introduced me to Vladimir Putin and we began working together. I noticed immediately Putin's fantastic work. He was brilliant at formulating ideas, at analysing and arguing his case."
Was there a moment, I ask, when you thought this man could be president?
"Yeltsin had several candidates in mind, like Boris Nemtsov, Sergei Stepashin and Nikolai Aksenenko. Yeltsin and I talked a lot about possible successors. At one point we discussed Putin.
"Yeltsin asked me: 'What do you think about Putin?' I think he's a superb candidate, I replied. I think you should consider him. It's clear from the way he does his job that he's ready for more difficult tasks."
Did Putin's KGB past put him off?
"A lot of KGB agents, like Putin, had left the organisation, realising it was discredited. The fact that he was ex-KGB meant nothing. Putin had shown himself to be a liberal and a democrat, who wanted to continue market reforms."
The secret succession
In August 1999, Boris Yeltsin appointed Vladimir Putin prime minister. It was a clear sign that President Yeltsin was preparing Mr Putin for the Kremlin.
Mr Yeltsin was not due to leave office for another year, but in December 1999 he took the surprise decision to go early.
"Three days before New Year, Yeltsin summoned Putin to his country residence. He asked me to be present, and his new chief of staff, Alexander Voloshin. He told Putin that he wouldn't hang around until July. He'd resign on 31 December.
"Only a tiny group of people knew: me, Voloshin, Putin and Yeltsin's daughter Tatyana. Yeltsin didn't even tell his wife."
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Mr Yumashev was entrusted with writing Yeltsin's resignation speech.
"It was a hard speech to write. It was clear the text would go down in history. The message was important. That's why I wrote the famous line 'Forgive me'.
"Russians had suffered such shock and stress during the 1990s. Yeltsin had to speak about this."
On New Year's Eve 1999, Boris Yeltsin recorded his final TV address in the Kremlin.
"It came as a shock to everyone present. Except me, who'd written the speech. People burst into tears. It was an emotional moment.
"But it was important that the news didn't leak. There were still four hours before the official announcement. So, all the people in the room were locked in. They weren't allowed to leave. I took the tape and drove to the TV station. The speech was broadcast at midday."
Vladimir Putin became acting president. Three months later, he won the election.
A member of 'The Family'?
Valentin Yumashev is often referred to as a member of "The Family": Boris Yeltsin's inner circle that, allegedly, exerted influence over him towards the end of the 1990s.
Mr Yumashev dismisses "The Family" as "a myth, an invention".
But there's little doubt that during the 1990s, with President Yeltsin in failing health, the Kremlin leader placed his trust, increasingly, in a narrow circle of relatives, friends and business figures.
Boris Yeltsin (L) and Mr Putin at a Victory Day parade in Moscow's Red Square in May 2000
"Putin's entourage doesn't exert influence like this," explains political scientist Valery Solovei.
"There are two categories of people Putin leans towards: childhood friends, like the Rotenberg brothers and those who served in the Soviet KGB.
"But he doesn't overestimate their loyalty. Yeltsin trusted members of his family. Putin trusts no-one."
'No regrets - Russians trust Putin'
Mr Putin has remained in power, as president or prime minister, for 20 years. In that time, he has built a system of power that revolves around him. Under his watch, Russia has become an increasingly authoritarian state, with fewer democratic rights and freedoms.
"Yeltsin believed he had a mission, and so does Putin," Mr Solovei says. "Yeltsin saw himself as Moses: he wanted to lead his country out of its communist slavery.
"Putin's mission is to return to the past. He wants to avenge what he calls 'the greatest geopolitical catastrophe of the 20th Century', the fall of the USSR. He and his entourage, former KGB officers, believe the destruction of the Soviet Union was the work of Western intelligence services."
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The Vladimir Putin of today is barely recognisable from the liberal figure Mr Yumashev remembers. So, does Mr Putin's former boss regret giving him a job?
"I have no regrets," Mr Yumashev tells me, adding: "It's clear that Russians still trust Putin."
Still, Mr Yumashev thinks that Boris Yeltsin's resignation should serve as a lesson to all Russian presidents, the lesson being "that it's very important to step down and make way for younger people. For Yeltsin this was incredibly important."
