Why is Putin making them?
Analysts say Mr Putin, 67, wants to secure a political future for himself and Russia when he is constitutionally mandated to step down in 2024.
“This is the official start of the transition of power,” Alexander Baunov, an analyst at the Carnegie Moscow Centre, wrote on Twitter. “There can be no second Putin. Putin’s four terms were needed to help the country recover from the collapse of the Soviet Union. From now on, the maximum reign will be 12 years.”
Speculation over Mr Putin’s future has convulsed the Kremlin ever since he won re-election to a fourth and final term in 2018. His approval ratings sunk to record lows last year amid a moribund economy; attempts to revive it through a Rbs25.7tn ($608.5 billion) spending programme have so far sputtered.
The uncertainty has also set off battles among his underlings as they jockey for position, suggesting that Mr Putin may have wanted to pre-empt further clashes. “There are lots of obvious signs that internal infighting is getting fairly severe,” said Ekaterina Schulmann, a political scientist.
“Interest groups are fighting to the death, the level of repression is high, and people are putting each other in jail for long terms. This could transform into a coalition that might be hostile to him, or the mere uncertainty could contribute to instability if it’s allowed to go on for too long.”
Will Putin cede power when his term expires?
Mr Putin has never considered relinquishing power, according to two longtime confidants.
“He thinks things will collapse without him,” one of the people said. “There won’t be serious change in the country without pressure. The majority of people don’t care. Revolutions take place when there is no bread and the shelves are empty.”
While Mr Putin could theoretically become prime minister again, analysts say the most likely move will see him head up the revamped State Council. If he did so, Mr Putin would be taking after Kazakhstan’s Nursultan Nazarbayev, who stepped down last year after almost three decades in power to become “leader of the nation” for life and appointed a successor.
“He wants Russia to have a strong president and will choose a successor who is loyal, patriotic, and will support the transition,” said Tatiana Stanovaya, founder of Russian political analysis firm R. Politik. “Putin will stay within the system to determine some strategic questions and has the right of veto in case he has any disagreements with the successor.”
Why did Medvedev resign as prime minister?
Mr Medvedev is arguably Mr Putin’s closest political ally. A colleague since their days in the Leningrad mayor’s office in the 1990s, Mr Medvedev spent four years as president from 2008 to 2012 before swapping jobs with Putin in a pre-determined “castling”.
Upon returning to the Kremlin amid mass street protests, Mr Putin undid most of Medvedev’s liberal, pro-western legacy and ramped up Russia’s confrontational stance against the west.
Though Mr Medvedev clearly continued to enjoy Mr Putin’s trust, his demotion hamstrung him politically and made him a rumoured candidate for the chopping block.
“Everyone has been sick of Medvedev for ages,” Ms Stanovaya said. “He should have resigned after the  presidential elections, but Putin needed to resolve who his replacement would be and where he would put Medvedev. Now Putin has decided what to do with his future and they are going their separate ways.”
Mr Medvedev’s new job, however, suggests he still has some distance left to run. Mr Putin created a position for him as deputy head of the security council and said Mr Medvedev’s presidential experience made him uniquely qualified to handle the brief.
Who will succeed Putin?
Mr Medvedev’s replacement is Mikhail Mishustin, a technocrat who has won plaudits for modernising Russia’s tax office. “[Mishustin’s appointment] is a surprise and I think business will welcome it,” said the chief executive of one of Russia’s biggest companies. “The man is by far the most qualified and smart in the current landscape.”
But Mr Mishustin’s complete lack of political experience means he is unlikely to be groomed as Mr Putin’s successor, Ms Schulmann said. “There are some people that, if he appointed them, it would be a political message and everyone would understand what was happening. Mishustin isn’t that. It’s not a political declaration.”
Mr Putin has yet to indicate whether he will cede power at all and has earmarked no clear successor. Apart from Medvedev, dozens of names have been floated including Moscow mayor Sergei Sobyanin, defence minister Sergei Shoigu, deputy prime minister Dmitry Kozak, as well as Alexei Dyumin, Mr Putin’s former bodyguard, and his children Maria and Ekaterina, who have recently made several appearances on state TV under pseudonyms.
“Putin won’t create a figure who could start competing with him,” Gleb Pavlovsky, a former Kremlin spin-doctor, said. “He did that with Medvedev and it didn’t work.”
As long as Mr Putin is calling the shots, the changes can be only superficial, he added. “Everything is run through calls from the presidential administration. If they don’t get rid of that then you can rewrite the constitution as much as you want — everything will still stay the same.” Additional reporting by Henry Foy