The House voted to impeach Donald Trump on Wednesday 13 January, in reaction to his incitement of the Capitol riots just one week prior. This was the first time an American president had been impeached twice.
A mob of pro-Trump supporters breached the US Capitol on Wednesday 6 January during the confirmation of electoral college votes, putting a hold to the process to confirm Joe Biden’s presidential victory for several hours.
The rioters attacked the Capitol after attending a rally led by Mr Trump, who urged his supporters to “walk down to the Capitol” and told them: “You have to show strength, and you have to be strong.”
Numerous politicians and staff members were forced to barricade themselves in offices to hide from the rioters, some of whom were carrying guns and other weapons. Five people died and numerous others were injured in the riots.
Several politicians blamed Mr Trump, who left office on 20 January, for the insurrection that took place directly after his rally, and Democratic officials quickly drew up plans for impeachment.
House Democrats charged the president with “incitement of insurrection” and voted on 13 January to impeach Mr Trump by 232 to 197, with 10 Republicans breaking party lines.
The process moves to the Senate for an impeachment trial overseen by Vermont senator and president pro tempore of the Senate, Patrick Leahy, which will begin on 9 February.
John Roberts, the US Supreme Court chief justice, presided over Mr Trump's first impeachment trial in 2019, but decided to skip this one because Mr Trump is no longer in office.
Only three presidents in US history have been impeached by the House, including President Trump in 2019, but they were all acquitted by the Senate in the subsequent trials.
James Buchanan and Richard Nixon were also investigated in 1860 and 1973-1974, respectively, but were not impeached by the House. Nixon resigned before he could be impeached and was acquitted by Gerald Ford, who had served as his vice president.
Which US presidents have been impeached and has anyone been impeached twice?
Andrew Johnson, the 17th US president, was impeached by the House in March 1868 for “high crimes and misdemeanours,” after he was accused of violating the Tenure of Office Act.
The act, which was later deemed to be invalid by the US Supreme Court, restricted the power of the president to remove certain office-holders without Senate approval.
Johnson was deemed by the House to have violated the act by trying to remove the US secretary of war, Edwin Stanton, without receiving approval from the Senate.
He was the first president to be impeached on 2 March 1868 when the House formally adopted the articles of impeachment and forwarded them to the Senate.
Johnson’s Senate trial began just three days later, but he was not convicted, as the motion failed to receive two-thirds of votes in favour of impeachment on three of the 11 articles, before the rest were abandoned without voting.
The Tenure of Office Act was finally repealed in 1887. Johnson remained as president until the end of his first and only term in March 1869.
Bill Clinton, the 42nd US president, was impeached by the House on 8 October 1998, for “high crimes and misdemeanours” on accusations of lying under oath and obstruction of justice.
The accusation related to a lawsuit that was filed by civil servant Paula Jones in 1994, which alleged that he had sexually harassed her, and from his testimony in which he denied that he had engaged in an affair with White House intern Monica Lewinsky between 1995 and 1997.
Mr Clinton initially denied that he had engaged in an affair with Ms Lewinsky, famously saying: “I did not have sexual relations with that woman, Miss Lewinsky,” however he later admitted that he had lied.
He was the second US president to be impeached, but was later acquitted by the Senate on 12 February 1999, as the two-thirds majority of votes required was not met.
Mr Clinton remained president until the end of his second term on 20 January 2001.
Donald Trump, the 45th US president, was impeached by the House on 18 December 2019, after two articles were adopted, accusing him of abuse of power and obstruction of Congress.
The impeachment stemmed from accusations that Mr Trump pressured Ukrainian officials into investigating his soon-to-be election opponent, Joe Biden.
On 16 January 2020, the articles were submitted to the Senate, and the trial started shortly after.
However, on 5 February 2020, Mr Trump was acquitted on both counts as neither received the two-thirds of votes needed to convict him in the Republican-led Senate.
Less than a year later, Mr Trump is the first US president in history to be impeached twice, after the House voted on allegations including “inciting violence against the government”.
Mr Trump was impeached by the House on 13 January 2021, with ten Republicans voting in favour of the president’s impeachment.
Although some Republican senators have suggested that they might vote to convict Mr Trump, it is unlikely that the motion will receive the two-thirds of votes needed with a tightly-contested Senate.
Mr Trump's trial begins on 9 February, just less than three weeks after he left office and relocated to Florida.