Vladimir Putin has been sworn in for his fourth term as president of Russia at a ceremony in the Grand Kremlin Palace in Moscow.
Video footage released by Russian television showed Mr Putin’s distinctive walk along the Great Kremlin Palace’s long corridors, thanking supporters as they applauded him.
Mr Putin has been in power in Russia since 1999, whether as prime minister or president and is Russia’s longest-serving leader since Soviet dictator Joseph Stalin.
After winning a landslide victory in March, Mr Putin, 65, is expected to continue to control Russia until at least 2024, despite protests on Saturday amid a crackdown on encrypted messaging app Telegram.
Supporters see Mr Putin as a father-of-the-nation figure who has restored national pride and expanded Moscow’s global power.
He has pledged new economic reforms that would boost living standards across Russia.
The Kremlin has planned a low-key inauguration ceremony that will not include a lavish Kremlin reception in an apparent effort to eschew any bad publicity.
A respectful gun salute was held outside the Kremlin at Mr Putin was sworn in.
The ceremony is being watched across the world as the Russian leader finds himself increasingly at odds with much of the international community.
Russia’s annexation of Crimea and Mr Putin’s support for Syria’s Assad, as well as the use of a chemical weapon it manufactured in an attempted assassination in Salisbury, have resulted in sanctions against the country.
His inauguration follows nationwide rallies and protests which resulted in the arrests of at least 1,200 demonstrators.
Russia’s interior ministry said about half of the 1,200 arrests happened in Moscow, but monitoring group OVD-Info put the number at more than 1,600 across 20 cities.
Protest leader Alexei Navalny was arrested in Moscow’s Pushkin Square on Saturday, but he later tweeted that he had been released and will face charges of organizing an unauthorized meeting and of resisting police.
Mr Putin’s inauguration comes ahead of Russia hosting the World Cup 2018 this summer.
In a widely expected win in March, Mr Putin secured more than 76.66% of the vote and a turnout of 67.47%, the Central Election Commission said.
The result came amid allegations of election violations, including ballot-box stuffing and forced voting.
Addressing a crowd near Moscow’s Red Square shortly after the count, Mr Putin said his victory was a vote of confidence in his achievements.
“It’s very important to maintain this unity,” he said.
“We will think about the future of our great Motherland,” he said, before leading the crowd in repeated chants of “Russia!”