Impeachment proceedings against President Donald Trump formally began on Thursday.
Seven House impeachment managers, who will serve as prosecutors, presented the articles of impeachment in the Senate slightly after noon.
Rep. Adam Schiff, a leading House manager, read aloud the charges — abuse of power and obstruction of Congress — against the president.
"Using the powers of his high office, President Trump solicited the interference of a foreign government, Ukraine, in the 2020 United States presidential election," he said, laying out the abuse of power charge.
In the second article, Schiff described Trump's efforts to hinder the congressional investigation into his actions with Ukraine, saying the president "directed the unprecedented, categorical, and indiscriminate defiance of subpoenas issued by the House of Representatives pursuant to its sole power of impeachment."
He added, "President Trump thus warrants impeachment and trial, removal from office, and disqualification to hold and enjoy any office of honor, trust, or profit."
Later in the afternoon, escorted by several senators, Supreme Court Chief Justice John Roberts was sworn in as presiding officer by Sen. Chuck Grassley.
Roberts then administered the oath to all 100 senators as jurors in the president’s trial, asking, "Do you solemnly swear that in all things appertaining to the trial of the impeachment of Donald John Trump, president of the United States, now pending, you will do impartial justice according to the Constitution and laws, so help you God?"
In groups of four, the senators were called forward to sign an oath book. Roberts then adjourned the Senate until 1 p.m. on Tuesday.
The Senate now delivers notice to Trump, summoning him to trial.
Thursday's procedure was largely ceremonial; the real action will start next week, when the Senate returns after the long weekend and votes on rules for the trial. Under current impeachment rules, the trial will run Monday through Saturday every week. It may go on for several weeks.