Washington (CNN) FBI Director James Comey testified before the House Intelligence Committee Monday, publicly confirming for the first time that the bureau is investigating the relationship between President Donald Trump's advisers and Russia to see if those ties played a role in Moscow's efforts to interfere with the 2016 US election.

During the hearing, Comey was asked for details related to the actions of several individuals who are either currently members of the Trump administration or were tied to his campaign team. Paul Manafort, Michael Flynn, Jeff Sessions, Roger Stone and other figures in the Trump orbit are under scrutiny for their interactions with Russia. They all deny anything improper took place. So what do we know happened when?

2016

Alabama Sen. Jeff Sessions becomes the first sitting US senator to endorse Republican presidential candidate Donald Trump's campaign. Sessions had already been a supporter and adviser to Trump.

March 21: Trump Trump tells The Washington Post editorial board that Walid Phares and Carter Page will be among his campaign's advisers for foreign policy.

March 28: Trump hires Manafort to head the delegate efforts for his Republican primary campaign.

May 19: Trump, now the presumptive GOP nominee, gives Manafort a promotion: Trump, now the presumptive GOP nominee, gives Manafort a promotion: campaign chairman and chief strategist

June 15: A cybersecurity firm hired by the DNC A cybersecurity firm hired by the DNC posts a public notice on its website describing an attack on the political committee's computer network by two groups associated with Russian intelligence. According to the post, two Russian-backed groups called "Cozy Bear" and "Fancy Bear" tunneled into the committee's computer system. In response, a blogger called Guccifer 2.0 claims that he alone conducted the hack, not the Russians. As proof, he posts internal DNC memos and opposition research on Trump. Furthermore, Guccifer 2.0 claims to have passed along thousands of files to WikiLeaks. Trump offers his own theory on the origins of the attack, suggesting in a statement that the DNC hacked itself to distract from Hillary Clinton's email scandal.

June: Private cybersecurity firms provide the FBI with details of the forensic evidence they gathered from DNC servers. Private cybersecurity firms provide the FBI with details of the forensic evidence they gathered from DNC servers. The DNC "rebuffed" a request from the FBI to examine its computer services after it was allegedly hacked by Russia during the 2016 election, a senior law enforcement official later told CNN.

June 20: After Trump campaign manager Corey Lewandowski is abruptly fired, After Trump campaign manager Corey Lewandowski is abruptly fired, Manafort emerges as Trump's top campaign official.

July 8: The Telegraph reports Page gave a lecture in Moscow that slams US policy toward Russia. Page "lamented that the West 'unnecessarily perpetuated Cold War tendencies' in their dealings with Russia, and called instead for 'mutual respect' in order to get 'mutual benefits,'" The Telegraph reports.

July 11: At an RNC Platform Committee meeting, a Cruz delegate proposes an amendment that called on the US government to send lethal weapons to Ukraine in response to Russian "military aggression" in the region. Trump campaign aides initiated a process to stop that language from officially being adopted, according to CNN reporting. The final version of the platform strips out the reference to arming Ukraine and calls on the US to provide "appropriate assistance" instead. The platform does support US sanctions on Russia and includes a threat of more sanctions if Russia continues meddling in Ukraine. At the time, Manafort denies that the campaign had any involvement in the change. But in March 2017, Trump campaign adviser At an RNC Platform Committee meeting, a Cruz delegate proposes an amendment that called on the US government to send lethal weapons to Ukraine in response to Russian "military aggression" in the region. Trump campaign aides initiated a process to stop that language from officially being adopted, according to CNN reporting. The final version of the platform strips out the reference to arming Ukraine and calls on the US to provide "appropriate assistance" instead. The platform does support US sanctions on Russia and includes a threat of more sanctions if Russia continues meddling in Ukraine. At the time, Manafort denies that the campaign had any involvement in the change. But in March 2017, Trump campaign adviser JD Gordon tells CNN that he is one of the campaign aides who stepped in to defeat the amendment that included references to "lethal defensive weapons" for Ukraine.

Between July 18-21: Sessions meets with Russian ambassador to the US Sergey Kislyak twice on the sidelines of the Republican National Convention in Cleveland, Ohio. Gordon and Page, national security advisers to the Trump campaign, Sessions meets with Russian ambassador to the US Sergey Kislyak twice on the sidelines of the Republican National Convention in Cleveland, Ohio. Gordon and Page, national security advisers to the Trump campaign, also meet with Kislyak during the convention. Phares allegedly attends as well, according to a later statement from Gordon.

July 22: Days before the Democratic National Convention, Days before the Democratic National Convention, WikiLeaks posts nearly 20,000 emails hacked from the DNC server. The documents include notes in which DNC chair Debbie Wasserman Schultz insults staffers from the campaign of Clinton rival Bernie Sanders and messages that suggest the organization was favoring Clinton rather than remaining neutral. Wasserman Schultz resigns in the aftermath of the leak.

July 25: The FBI announces it has launched an investigation into the DNC hack. Although the statement doesn't indicate that the agency has a particular suspect or suspects in mind, US officials tell CNN they think the cyberattack is linked to Russia

July 27: At a press conference in Florida, At a press conference in Florida, Trump appears to call on Russia to hack Democratic nominee Hillary Clinton's private emails: "I will tell you this -- Russia, if you're listening, I hope you're able to find the 30,000 e-mails that are missing. I think you will probably be rewarded mightily by our press. Let's see if that happens." Days later, Trump said he was joking.

August 5: Roger Stone, an informal Trump adviser, Roger Stone, an informal Trump adviser, writes a column for Breitbart News that repeats claims that Guccifer 2.0 -- and not Russia -- was behind the DNC hacks. US officials believe that Guccifer 2.0 is a front for Russian military intelligence.

August 8: During an event in Florida, During an event in Florida, Stone boasts in a speech that he "has communicated with (WikiLeaks founder Julian) Assange," and that more documents would be coming, including an "October surprise."

August 14: The New York Times reports on $12.7 million in secret cash payments earmarked for Manafort from a pro-Russian political party in Ukraine.

August 14-17: Stone exchanges private messages with Guccifer 2.0 on Twitter after the hacker was briefly banned from the social media platform. Months later, Stone posted Stone exchanges private messages with Guccifer 2.0 on Twitter after the hacker was briefly banned from the social media platform. Months later, Stone posted two screenshots of the conversation on his blog and downplayed the exchange.

August 15: Manafort Manafort denies having received payments from Ukraine and Russia, writing, "The suggestion that I accepted cash payments is unfounded, silly and nonsensical."

August 19: that FBI and Justice Department prosecutors are conducting an investigation into possible US ties to alleged corruption of the former pro-Russian President of Ukraine, including the work of Manafort's firm. That same day, CNN reports that FBI and Justice Department prosecutors are conducting an investigation into possible US ties to alleged corruption of the former pro-Russian President of Ukraine, including the work of Manafort's firm. That same day, Manafort resigns his position on Trump's campaign.

JUST WATCHED Paul Manafort firm under investigation in Ukraine probe Replay More Videos ... MUST WATCH Paul Manafort firm under investigation in Ukraine probe 01:42

August 21: In a In a Twitter post , Stone alludes to upcoming trouble for Clinton campaign manager John Podesta, saying "Trust me, it will soon (be) Podesta's time in the barrel."

September 8: Sessions meets again with Kislyak at his Senate office sometime during the month.

September 9: Guccifer 2.0 sends several messages to Stone about recent leaks. Stone sends a two-word response -- "pretty standard" -- according to a Guccifer 2.0 sends several messages to Stone about recent leaks. Stone sends a two-word response -- "pretty standard" -- according to a screenshot of the private Twitter conversation posted by Stone on his blog.

September 26: During a presidential debate with Clinton, During a presidential debate with Clinton, Trump questions whether the DNC cyberattack was carried out by a state-sponsored group or a lone hacker. "It could be Russia, but it could also be China. It could also be lots of other people. It also could be somebody sitting on their bed that weighs 400 pounds," he said.

October 3-5: Stone sends Stone sends two additional cryptic tweets predicting that action from Julian Assange and WikiLeaks will soon release more materials harmful to Clinton. "Payload coming," he tweeted.

October 7: the first batch of emails from Clinton campaign manager John Podesta. The anti-secrecy website went on to release thousands of additional emails on a near-daily basis for the duration of the election season. WikiLeaks releases the first batch of emails from Clinton campaign manager John Podesta. The anti-secrecy website went on to release thousands of additional emails on a near-daily basis for the duration of the election season.

The US intelligence community publicly blames Russia for election-related email hacks. "We believe, based on the scope and sensitivity of these efforts, that only Russia's senior-most officials could have authorized these activities," the DHS and DNI joint statement reads

October 10: Trump says he Trump says he "loves" WikiLeaks during a campaign rally in Wilkes-Barre, Pennsylvania, just days after the first batch of hacked Podesta emails are released.

November 29: A group of Democratic senators sends a letter to President Barack Obama calling on intelligence agencies to declassify information about "the Russian Government and the US election." Sources later tell CNN that new intelligence has been shared with lawmakers suggesting that Russia's purpose for meddling in the election was to sway voters towards Trump, rather than broadly undermining confidence in the system.

December: Trump's senior aide and son-in-law Jared Trump's senior aide and son-in-law Jared Kushner and Flynn sit down at Trump Tower with Kislyak, according to a senior administration official, who describes it as an "introductory meeting" and "kind of an inconsequential hello." The meeting lasts about 10 minutes, the official says.

December 1: CNN reports that Manafort has reemerged in Trump's orbit as a player shaping the new administration during the presidential transition period.

December 11: Sources tell CNN that although US intelligence agencies share the belief that Russia played a role in the computer hacks, there is disagreement between the CIA and the FBI about the intent of the meddling. While the CIA assessment shows that the Russians may have sought to damage Clinton and help Trump, the FBI has yet to find proof that the attacks were orchestrated to elect the Republican candidate, according to unnamed officials. Furthermore, some sources say the hackers also infiltrated the Republican National Committee's computers.

December 12: CNN reports that CNN reports that Russian hackers accessed computer accounts of Republican lawmakers and GOP organizations. A source with knowledge of the investigation says that even though hackers breached the GOP computers, they opted not to release documents en masse.

December 19: Kislyak and Flynn have a conversation in the wake of the shooting of the Russian ambassador to Turkey in which Flynn expresses his condolences, according to a Trump transition official. The call took place on December 19, Kislyak and Flynn have a conversation in the wake of the shooting of the Russian ambassador to Turkey in which Flynn expresses his condolences, according to a Trump transition official. The call took place on December 19, according to The Washington Post

December 25: Kislyak and Flynn Kislyak and Flynn exchange holiday pleasantries via text message on Christmas, according to multiple transition officials.

December 28: The Russian ambassador The Russian ambassador texts Flynn , according to a transition official.

December 29: The Obama administration announces The Obama administration announces new sanctions against Russia and the expulsion of 35 diplomats over the country's alleged interference in the 2016 US election. Flynn and Kislyak speak several times on the phone the same day, reportedly discussing the sanctions.

December 30: Russian President Russian President Vladimir Putin says Moscow would not expel American diplomats in response to US sanctions against Russia and would instead attempt to rebuild relations with Washington after Trump's inauguration. Trump tweets praise of Putin's move.

2017

January 6: The top US intelligence agency The top US intelligence agency releases a report concluding that Putin ordered a cyber campaign to help Trump and hurt Clinton in the US presidential election. The report also said the Russian military intelligence agency known as the GRU "used the Guccifer 2.0 persona and DCLeaks.com" to release material to influence the election "and relayed material to WikiLeaks." WIkiLeaks founder Julian Assange denied this finding in a Fox News interview in January. He said "Our source is not the Russian government. It is not state parties."

Trump receives an intelligence briefing at Trump Tower. Comey informs Trump about Russian hacking and gives Trump a summary of a dossier detailing allegations that Russian operatives claim to have compromising personal and financial information about him, multiple US officials with direct knowledge of the briefings tell CNN.

January 10: At Sessions' At Sessions' Senate confirmation hearing to become attorney general, Sen. Al Franken asks about a CNN report about intelligence community information that Trump campaign officials were in constant communication with Russians during the campaign. Sessions offers that he was a surrogate but never in contact with Russians.

January 12: The Washington Post first reports that phone calls took place the day the White House announced Russian sanctions.

January 13: Trump spokesman Trump spokesman Sean Spicer says Flynn's calls to Kislyak focused on the logistics of connecting Trump and Putin. "The call centered around the logistics of setting up a call with the President of Russia and the President-elect after he was sworn in, and they exchanged the logistical information," Spicer says. "That was it. Plain and simple."

January 15: Spicer confirms Flynn and Kislyak have been in communication, but US Vice President Mike Pence tells CBS that Spicer confirms Flynn and Kislyak have been in communication, but US Vice President Mike Pence tells CBS that the two men did not talk about sanctions.

"They did not discuss anything having to do with the United States' decision to expel diplomats or impose censure against Russia," Pence says.

January 23: Spicer, now the White House press secretary, reiterates that Flynn told him sanctions were not discussed in the calls. Three days after Trump officially becomes president, Spicer, now the White House press secretary, reiterates that Flynn told him sanctions were not discussed in the calls. Three days after Trump officially becomes president, US officials say investigators are scrutinizing several calls between Flynn and Russia's ambassador.

January 26: that Flynn misled administration officials regarding his communications with Kislyak and is potentially vulnerable to blackmail by the Russians, according to a person familiar with the matter. The message is delivered by acting Attorney General Sally Yates, who is fired on January 30 for refusing to enforce Trump's controversial travel ban barring citizens from seven Muslim-majority countries from entering the US. The Justice Department privately warns the Trump administration that Flynn misled administration officials regarding his communications with Kislyak and is potentially vulnerable to blackmail by the Russians, according to a person familiar with the matter. The message is delivered by acting Attorney General Sally Yates, who is fired on January 30 for refusing to enforce Trump's controversial travel ban barring citizens from seven Muslim-majority countries from entering the US.

February 8: The Senate The Senate confirms Sessions to be the US attorney general.

February 9: he had been misled by Flynn, according to two administration officials. Pence finds out he had been misled by Flynn, according to two administration officials.

February 13: Russia again denies the allegations that the men held conversations about sanctions, telling CNN: " Russia again denies the allegations that the men held conversations about sanctions, telling CNN: We have already said there haven't been any. " On the same day, reports surface of the Justice Department's warning to the administration regarding Flynn. As the reports emerge, Trump's counselor Kellyanne Conway tells MSNBC that Flynn "does enjoy the full confidence of the President," but around an hour later, Spicer says Trump is "evaluating the situation." Flynn resigns a few hours later , admitting he had "inadvertently briefed the vice president-elect and others with incomplete information" regarding the phone calls with Kislyak and apologizes.

JUST WATCHED Spicer: Trump concluded there was no trust Replay More Videos ... MUST WATCH Spicer: Trump concluded there was no trust 05:29

February 14: Spicer says Trump asked for Flynn's resignation because of Spicer says Trump asked for Flynn's resignation because of trust issues with his national security adviser. CNN reports that high-level advisers close to then-nominee Trump were in constant communication during the campaign with Russians known to US intelligence, according to multiple current and former intelligence, law enforcement and administration officials. Among those senior advisers regularly communicating with Russian nationals were Manafort and Flynn.

February 16: FBI officials tell CNN that they do not plan to FBI officials tell CNN that they do not plan to pursue charges against Flynn barring any new information, after he told agents he did not remember discussing sanctions with Kislyak.

February 24: CNN reports that the FBI CNN reports that the FBI rejected a recent White House request to publicly knock down media reports about communications between Trump's associates and Russians known to US intelligence during the 2016 campaign.

February 27: Members of the House Intelligence Committee Members of the House Intelligence Committee sign off on a plan to investigate Russia's alleged interference in the US elections, which includes examining contacts between Trump's campaign and Russia, and looking into who leaked the details. Committee chairman Devin Nunes brushes off calls by Democrats for an independent investigation.

JUST WATCHED Sessions reacts to reports he met with Russia Replay More Videos ... MUST WATCH Sessions reacts to reports he met with Russia 01:58

March 2: Sessions announces he Sessions announces he will recuse himself from any investigations relating to Russia and the Trump campaign. USA Today reports that Gordon and Page met with Kislyak during the Republican convention in July. Gordon tells CNN that, along with national security advisers Page and Phares, he stressed to the Russian envoy that he would like to improve relations with Russia. "This is not any different than anything I said publicly and on panels," Gordon says. Page confirms in an MSNBC interview that he met with Kislyak in Cleveland. Page tells CNN in a statement that he would not comment on any meetings and "never did anything improper" with regard to Russia.

March 3: Russian Foreign Minister Sergey Lavrov Russian Foreign Minister Sergey Lavrov pushes back at assertions that his country's US ambassador is a spy, and echoes Trump's contention that the controversy over contacts between Kremlin officials and Trump's campaign is "a witch hunt."

March 5: Kushner and Flynn met with the Russian ambassador to the United States at a time when the Trump administration's relationship with the Russians was under close scrutiny, a senior administration official says.

March 6: Sessions Sessions defends his answers about Russian contacts to the Senate Judiciary Committee as "correct" in a letter, as he seeks to tamp down questions after it came to light that he had met with the Russian ambassador twice last year.

March 7: Dmitry Peskov, spokesman for Putin, Dmitry Peskov, spokesman for Putin, tells CNN that "hysteria in official Washington and in the American media" is harming relations between the two nations.

March 10: The White House The White House acknowledges that President Donald Trump's transition team was aware that retired Lt. Gen. Michael Flynn engaged in work that would likely require him to register his consulting firm as a foreign agent before Flynn was tapped to serve as national security adviser.

March 16: Flynn Flynn was paid more than $33,750 by Russia's state-run broadcaster RT TV-Russia for a speech in Moscow in December 2015, Rep. Elijah Cummings, the ranking Democrat on the House Oversight Committee, says. The US intelligence community has long assessed RT to be a propaganda tool of the Kremlin, writing in its January report on Russian interference in the US election that the organization had participated in disinformation campaigns aimed at the US.

March 19: The Senate Intelligence Committee The Senate Intelligence Committee has asked Trump adviser Roger Stone to preserve any records he might have that could be related to the panel's investigation into Russian actions targeting the US election, Stone confirms to CNN.

March 20: FBI Director FBI Director James Comey confirms publicly for the first time that the FBI is investigating Russian interference in the election and, as part of that investigation, the FBI is probing "the nature of any links between individuals associated with the Trump campaign and the Russian government, and whether there was any coordination between the campaign and Russia's efforts." His bombshell came at a hearing of the House Intelligence Committee, where he also said the FBI will also determine "whether any crimes were committed."

Both Comey and National Security Agency Director Mike Rogers say there isn't any evidence that votes were changed in a series of key swing states that Trump won. Comey also confirms that the Russians wanted to help Trump and hurt Clinton, telling lawmakers "He -- Putin -- hated Secretary Clinton so much that the flip side of that coin was he had a clear preference for the person running against the person he hated so much."