Explainer: Who is Kremlin critic Alexei Navalny?

Alexei Navalny has been the most vocal and effective critic of Russia's government and President Vladimir Putin.

This was the moment Navalny boarded a plane from Berlin to Moscow,

his first return home since being near fatally poisoned by a Novichok nerve toxin,

a version of events the Kremlin rejects.

{Alexei Navalny} What a flight. I want to thank Germany, and I want to thank you all. I hope we will finish our flight safely. I am sure everything will be absolutely wonderful.

But he didn’t get far.

He was detained at passport control and said goodbye to his wife.

Now – he’s being held in this Moscow prison in pre-trial detention

despite calls from Western countries and the UN to free him.

The son of an army officer, the 44-year-old grew up in Obninsk, about 60 miles southwest of Moscow.

He has a degree in law and spent time in the United States on a fellowship at Yale.

Navalny is best known in Russia for producing detailed investigations into corruption.

His nickname for the ruling United Russia party – the "party of crooks and thieves" –

has become common coinage among his supporters.

His calls for restrictions on immigration and criticism over what some viewed as his overly nationalist views

led to his expulsion from the liberal Yabloko opposition party in 2007.

During anti-Putin demonstrations in 2011, he was one of the first protest leaders arrested.

In 2013, Navalny ran for mayor of Moscow.

He lost to the Kremlin-backed choice, but still got 27% of the vote despite little to no coverage on the state-controlled media outlets.

Since then Alexei Navalny has been barred from running for office.

Instead he uses social media to mobilize crowds of mostly young protestors.

Putin and the Kremlin make a point of never saying his name.

Navalny has been detained countless times for organizing public rallies and prosecuted repeatedly.

He - and his supporters – have also been physically attacked.

In 2017 a green antiseptic dye was thrown at him, causing him to temporarily lose sight in one eye.

In August 2020 he fell ill on a flight from Siberia.

He was flown to Berlin and treated for what tests showed to be Novichok - a poison developed in the Soviet Union.

A joint media investigation said it had identified a team of assassins from Russia's FSB security service.

Putin dismissed the investigation as a smear, saying: "If someone had wanted to poison him, they would have finished him off."