Here is a timeline of the events being investigated in the impeachment inquiry:
April 21, 2017
President Trump sits for an interview with the Associated Press, and in the course of that interview brings up a debunked conspiracy theory about Ukrainian interference in the 2016 election.
Rudy Giuliani participates in a Skype call with Viktor Shokin, who had been Ukraine’s top prosecutor until he was removed from office for failing to tackle corruption.
Rudy Giuliani meets with Yuriy Lutsenko, Ukraine’s top prosecutor at the time, and begins his own investigation into the Bidens.
March 31, 2019
Ukraine holds the first round of its Presidential elections, and a comedian by the name of Zelenskiy comes out ahead of the incumbent president, Petro Poroshenko. The race goes into a runoff.
April 7, 2019
In an interview on Fox News, Giuliani suggests that former Vice President Joe Biden had sought to have Viktor Shokin removed from his position as Ukraine’s top prosecutor because Shokin had been investigating a Ukrainian gas company called Burisma, which Biden’s son sat on the board of. There is no evidence to support the claim.
April 21, 2019
Zelenskiy is elected the new president of Ukraine, and President Trump calls him to congratulate him.
April 25, 2019
President Trump calls into Sean Hannity’s television show, and talks about rumors that Ukraine “collusion” in the 2016 U.S. presidential election, and states that he expects Attorney General William Barr will look into it.
May 6, 2019
Marie Yovanovitch, the U.S. Ambassador to Ukraine, is recalled by the State Department, ends her assignment in Kyiv, and returns to the United States.
May 9, 2019
Giuliani tells the NY Times that he will be traveling to Ukraine to meet with President-elect Zelenskiy and hopes to push for inquiries into the origins of the Russia investigation and the Biden family’s ties to Burisma.
May 10, 2019
Giuliani cancels his trip to Ukraine.
May 14, 2019
Trump is alleged to have instructed Vice President Pence to cancel his trip to President Zelenskiy’s inauguration, and Energy Secretary Rick Perry goes in his place.
May 19, 2019
In an interview on Fox News, President Trump brings up Biden and Ukraine, alleging Biden had corruptly sought to have Viktor Shokin removed as Ukraine’s top prosecutor because Shokin had been investigating Burisma, which Hunter Biden sat on the board of. In fact, Biden had sought the removal of Shokin for turning a blind eye to corruption, and Biden’s efforts were consistent with the goals of both the International Monetary Fund and European allies.
May 28, 2019
William Taylor, a longtime diplomat with decades of experience, meets with Secretary of State Mike Pompeo and reluctantly agrees to lead the embassy in Kyiv in the wake of Marie Yovanovitch being recalled to the United States.
May 29, 2019
President Trump sends a letter to President Zelenskiy inviting him for a White House meeting, but no date is set.
June 12, 2019
In an interview with ABC’s George Stephanopoulos, President Trump states that he would consider taking damaging information on a political rival from a foreign government.
June 18, 2019
The Department of Defense announces $250 million in aid will be provided to Ukraine to support the country’s defensive capabilities.
June 21, 2019
Giuliani sends out a tweet claiming that the President of Ukraine was remaining silent on investigations into 2016 election interference and Joe Biden.
July 10, 2019
A White House meeting takes place between Rick Perry, John Bolton, Kurt Volker, Gordon Sondland, and several top Ukrainian officials, including Andrey Yermak. In this meeting, Sondland connected a White House meeting between the two Presidents with “investigations.” National Security Advisor John Bolton abruptly ended the meeting and told his deputies to “brief the lawyers.”
July 18, 2019
President Trump places a hold on nearly $400 million in aid to Ukraine.
Taylor sets into motion a series of high-level meetings with top officials to address the hold, and there is anonymous agreement the hold needs to be lifted, but a joint meeting including the President proves to be difficult to schedule, causing the hold remain in effect until sometime in September.
At this point, it remains unclear when exactly the Ukrainians learned that a hold had been placed on the aid, but reporting in the New York Times suggests that the Ukrainians became aware of the hold sometime in August.
July 19, 2019
Volker and Giuliani meet over breakfast to discuss Ukraine, and Volker subsequently connects Giuliani with Yermak, an aid of Zelenskiy.
Later that day, Volker texts ambassadors Sondland and Taylor to discuss the upcoming call between the two Presidents, and stresses the importance that Zelenskiy tell Trump that he’ll help with the investigation.
July 20, 2019
In a phone call between Ukranian National Security Adviser Alexander Danyliuk and William Taylor, Danyliuk conveys that President Zelenskiy did not want to be used as a pawn in the upcoming U.S. election. Taylor proceeds to text Sondland and Volker to inform them of Zelenskiy’s concerns.
July 24, 2019
Robert Mueller testifies before the House Judiciary and Intelligence committees regarding Russian interference in the 2016 election.
July 25, 2019
8:36am: Volker sends a text message to Yermak stating that he had “Heard from White House - assuming President Z convinces trump he will investigate / 'get to the bottom of what happened' in 2016, we will nail down a date for visit to Washington.”
9:03am - 9:33am: President Trump and President Zelenskiy have a half hour phone conversation in which they discuss the investigation of corruption and a planned visit by President Zelenskiy to the United States. In the course of that conversation, President Trump said “I would like you to do us a favor though…” and then followed with a request that the Ukrainians look into an issue relating to CrowdStrike and coordinate with Attorney General Barr.
10:15am: Yermak sends a text message to Volker indicating that the phone call had gone well, and that President Zelenskiy was proposing Sept. 20-22 for the dates of his upcoming visit to the White House.
July 26, 2019
President Zelenskiy meets with Taylor and Volker, expresses that he was happy with the call, and brings up the promised face-to-face meeting between the two Presidents that had been promised in May.
August 9-17, 2019
State Department officials, Giuliani and Yermak discuss a statement that Ukraine could make announcing an investigation into Burisma and Ukrainian meddling in the 2016 U.S. presidential election.
Sondland tells Volker that Trump “really wants the deliverable.”
The Ukranians make clear that they want the date of a White House meeting set before they’ll release the statement announcing the investigations.
Volker informs Taylor by text message that Yermak asked that the United States submit an official request for the investigations. In his written testimony, Taylor claimed the request struck him as improper, and recommended staying clear of such a request.
August 12, 2019
Michael Atkinson, the inspector general for the intelligence community, receives an anonymous whistleblower complaint alleging “the President of the United States is using the power of his office to solicit interference from a foreign country in the 2020 U.S. election.”
August 22nd, 2019
A high-ranking National Security Council official tells Taylor that the “President doesn’t want to provide any security assistance at all.”
August 27, 2019
John Bolton meets with President Zelenskiy in Kyiv, but security assistance is not discussed.
August 28, 2019
Politico reports the holdup on U.S. military aid going to Ukraine.
August 29, 2019
Yermak sends a text to Volker with a link to the Politico story and asks to talk. He also expresses his concerns to Taylor.
Trump had been scheduled to meet with President Zelenskiy during the trip to Poland to commemorate World War II. President Trump cancels his trip so that he can monitor an incoming hurricane, and Vice President goes in his place.
September 1, 2019
Vice President Pence meets with President Zelenskiy in Warsaw, Poland. Security assistance for Ukraine is brought up, and VP Pence agrees to speak with President Trump about it.
Taylor is told that Sondland met with Yermak in Warsaw, and told the Ukranian official that “the security assistance money would not come until President Zelenskyy committed to pursue the Burisma investigation.”
Taylor sends a text message to Sondland asking for confirmation of what he’s heard, asking, “Are we now saying that security assistance and WH meeting are conditioned on investigations?”
In reply, Sondland simply says, “Call me.”
Taylor calls Sondland, and as he would later describe in his written testimony, “Ambassador Sondland told me that President Trump had told him that he wants President Zelenskyy to state publicly that Ukraine will investigate Burisma and alleged Ukrainian interference in the 2016 U.S. election.” Sondland allegedly told him “everything” was contingent on “such an announcement, including security assistance.” Sondland would go on to explain that Trump wanted to put Zelenskiy “in a public box” with respect to the investigations.
September 2, 2019
Vice President Pence tells reporters that Biden was not discussed in his meeting with President Zelenskiy, but that they did discuss “corruption” and the U.S.’s financial support for Ukraine.
September 8, 2019
Sondland informs Taylor that he’d informed Zelenskiy and Yermak that “although this was not a quid pro quo, if President Zelenskyy did not 'clear things up' in public, we would be at a ‘stalemate.’”
Taylor testified that he understood that a “stalemate” meant Ukraine wouldn’t be getting the security assistance.
Sondland told Taylor that the conversation had concluded with President Zelenskiy agreeing to make a public statement about the investigations on CNN.
September 9, 2019
Congressional intelligence committees are formally notified of the existence of the whistleblower complaint.
At 12:47am, Ambassador Taylor sends Gordon Sondland a text message that says, "As I said on the phone, I think it's crazy to withhold security assistance for help with a political campaign.”
Sondland speaks with Trump before responding.
At 5:15am, Sondland replies, stating "The President has been crystal clear no quid pro quo's of any kind" adding "I suggest we stop the back and forth by text."
September 11, 2019
The White House releases the hold on funding for Ukraine, but without explanation for what had changed to bring about the release in funding.
September 13, 2019
Rep. Adam Schiff, the chairman of the House Intelligence Committee, subpoenas Joseph Maguire, the acting director of national intelligence, demanding he provide the suppressed whistleblower complaint to Congress. Prior to this moment, Maguire had refused to turn over the complaint, citing guidance from the Justice Department as the basis for his refusal.
September 18, 2019
The Washington Post reports on the Whistleblower complaint.
September 22, 2019
While departing the White House, President Trump speaks with reporters and refers to the July 25th call as “absolutely perfect” and “a beautiful, warm, nice conversation.”
September 24, 2019
Speaker of the U.S. House of Representatives, Nancy Pelosi (D-CA) announces the start of a formal impeachment inquiry.
September 25, 2019
The White House releases a rough transcript of the call that had taken place between President Trump and President Zelenskiy on July 25th.
September 26, 2019
The House Intelligence Committee releases the Whistleblower Complaint.
December 11, 2019
House Judiciary begins debate on the Articles of Impeachment.
December 13, 2019
House Judiciary approves Articles of Impeachment.
December 18, 2019
The full U.S. House of Representatives debates the Articles of Impeachment and then votes to impeach.
January 16, 2020
House Impeachment Managers hand-deliver the articles to the Senate, a day after being appointed. U.S. Supreme Court Justice John Roberts and the U.S. Senators are sworn in.