The special counsel Robert Mueller filed new documents on Tuesday, describing criminal conduct by the former national security adviser Michael Flynn and the nature of Flynn’s cooperation over the last year with investigators.

Here are key moments in the Flynn case:

10 December 2015

Michael Flynn is seated next to Vladimir Putin at a dinner in Moscow to celebrate the 10th anniversary of the Kremlin-linked English-language news service RT. “I didn’t even really talk to him,” Flynn later said. He was paid $45,000 for the appearance.

February 2016

Flynn, a former director of the Defense Intelligence Agency, joins the Trump presidential campaign as an adviser on national security issues, lending heft to the insurgent candidate’s thin roster of aides

April 2016

In the final seven months of the presidential campaign, Flynn and other aides will hold 18 phone and email conversations with Russian operatives, Reuters reports.

Summer 2016

US spies observe Russian conversations about whether and how to use the campaign chairman, Paul Manafort, and Flynn to their advantage.

19 September 2016

Flynn meets Turkish contacts in New York and discusses US policy on the Islamic cleric Fethullah Gülen, a green-card holder residing in Pennsylvania. Flynn was reportedly paid $530,000 to consult for a Turkish businessman in a deal directed by the Turkish government. Flynn does not disclose his Turkish contracts until after his resignation from office, with prosecutors closing in.

18 November 2016

Trump names Flynn national security adviser.

December 2016

Flynn holds conversations about US sanctions on Russia with ambassador Sergey Kislyak. Vice-President Mike Pence will later say Flynn misled him as to the nature of the talks.

Flynn also meets Turkish contacts in New York, the Wall Street Journal reports. The special counsel is investigating Flynn for his alleged role in a deal to somehow turn Gülen over to Ankara in exchange for $15m.

29 December 2016

Flynn speaks with Kislyak on the phone five times, on the day the Obama administration retaliates for Russian tampering in the 2016 election by expelling 35 Russian diplomats and announcing new sanctions against Russian intelligence services and agencies involved in hacking.

15 January 2017

Pence goes on TV and says Flynn and Kislyak “did not discuss anything having to do with the United States’ decision to expel diplomats or impose censure against Russia”.

On campaign contacts with Russians who wanted to meddle, Pence says: “Well, of course not. I think to suggest that is to give credence to some of these bizarre rumors that have swirled around the candidacy.”

Late January 2017

Flynn is interviewed by the FBI about his Russia contacts. He later admits to telling multiple lies in the interview, including about conversations he had with Kislyak about US sanctions on Russia and about a United Nations resolution condemning Israel.

26 January 2017

The acting attorney general, Sally Yates, warns the White House about Flynn and his conversations with Russian operatives.

After the inauguration

The FBI is asked to review Turkey’s extradition request for Gülen.

13 February 2017

Flynn resigns.

14 February 2017

The FBI director, James Comey, will later say Trump told him of Flynn: “I hope you can see your way clear to letting this go, to letting Flynn go. He is a good guy. I hope you can let this go.”

16 February 2017

Trump is asked at a news conference “whether you are aware that anyone who advised your campaign had contacts with Russia during the course of the election?” The ensuing exchange is recorded in a White House transcript:

Trump: “Well, I told you, Gen Flynn obviously was dealing. So that’s one person. But he was dealing – as he should have been …

Questioner: “During the election?”

Trump: “No, no, nobody that I know of.”

Questioner: “So you’re not aware of any contacts during the course of the election?”

Trump: “Look, look, how many times do I have to answer this question?”

Questioner: “Can you just say yes or no on it?”

Trump: “Russia is a ruse. Yeah, I know you have to get up and ask a question, so important. Russia is a ruse. I have nothing to do with Russia, haven’t made a phone call to Russia in years. Don’t speak to people from Russia. Not that I wouldn’t, I just have nobody to speak to … I have nothing to do with Russia. To the best of my knowledge, no person that I deal with does.”

March 2017

Flynn registers as a foreign agent.

1 December 2017

Flynn pleads guilty to lying to the FBI and enters a deal to cooperate with Mueller.

4 December 2018

Mueller recommends no prison time for Flynn citing his “substantial assistance” to the Trump-Russia investigation and other criminal inquiries.