Dmitry Medvedev, who has lost his post as prime minister following the government's resignation, served a single term as president before standing aside to allow Vladimir Putin's return to the Kremlin in 2012.
Subsequently the 54-year-old served as prime minister with diminishing powers and authority. In recent months, his approval rating hovered around 28 percent, according to FOM polling agency.
It's unclear how much power Medvedev will have in the newly-created post of deputy head of the Russian security council after his momentous resignation Wednesday.
While president, Medvedev launched a campaign of modernisation to pull the country out of its post-Soviet stagnation but never escaped the shadow of his dominant mentor, to whom he remained resolutely loyal.
On his return to the Kremlin in 2012, Putin opted for continuity after reports that Medvedev could be on his way out fuelled by his absence during Putin's low-key presidential campaign.
First named prime minister by Putin after the strongman's return to the Kremlin in a notorious 2012 job swap, Medvedev played a relatively marginal role in the post in recent years.
In 2019, he visited Cuba and signed the Paris climate agreement on Russia's behalf, as well as making a controversial visit to far-eastern islands claimed by Japan.
In 2017, opposition politician and anti-corruption blogger Alexei Navalny accused Medvedev of controlling a luxury property empire in a YouTube video that has been viewed more than 27 million times and led to large-scale opposition protests.
'Freedom cannot be put off'
Medvedev was born on September 14, 1965 in Putin's home town of Leningrad to a family of teachers, training as a lawyer and then working in the city hall for five years under Putin from 1990-1995.
He owes his entire political career to the former KGB agent.
Putin took his protege to Moscow after being appointed prime minister in 1999 and Medvedev rapidly rose to be chairman of gas giant Gazprom. He also served as chief of staff at the Kremlin and as first deputy prime minister.
Anointed successor as Putin was not allowed to stand for more than two consecutive terms, Medvedev in 2008 won presidential elections on the back of Putin's support and his first act after taking office was to appoint the Russian strongman as prime minister.
He said Russia's economy had reached a "dead end" and required urgent reform if the country was going to move forward.
In one speech, he even seemed to compare himself to reforming Tsar Alexander II who in 1861 ordered the historic emancipation of the serfs and would ultimately be assassinated.
"We are trying to change our economy and change our political system. In essence we are continuing a political course that was set 150 years ago. Freedom cannot be put off for another day," he said.
But cynics pointed out that such words counted for little when Russia was still dominated by Putin and Medvedev himself played down the idea there was any radical difference in their visions.
His trademark modernisation programme was marked by some of the boldest statements ever by a Kremlin leader but was also mercilessly mocked by commentators for being short on actions.
While liberals and the West hoped Medvedev would reverse the increase in state control and erosion of civil liberties during Putin's previous rule, he showed little desire for a radical break with Putin's legacy.
- Modernisation drive -
Medvedev as president sought to promote a welcoming image for the country and championed a "reset" in relations with the United States, although his jarring statements at home appeared an attempt not to be outdone by Putin in the tough-talking stakes.
He sent Russian troops into Georgian territory in the 2008 war with Tbilisi, a decision that temporarily wrecked relations with the West but one the president insisted he took on his own.
On his watch, Moscow also abstained in a key UN Security Council vote on Libya in 2011 which paved the way for a NATO-led military intervention that Putin has relentlessly criticised since.
Keen to leave behind a legacy in Russia, Medvedev ordered the building of a technology hub in the town of Skolkovo outside Moscow.
Often seen proudly clutching his iPad -- a souvenir from a visit to Silicon Valley -- he has embraced Twitter, Instagram and Facebook, in contrast to the much less tech-savvy Putin.
However he won mockery for this from some Russians, as for his habit of dropping off to sleep during dull events.
An ambitious man, Medvedev suggested he would like to return to Russia's top job.
"Never say never," he told AFP in an interview in 2012.
Dmitry Medvedev, a longtime ally of Russian President Vladimir Putin, loses his job as prime minister with the government's resignation