WASHINGTON - History will record that this century's first impeachment trial of a sitting president began this week, but the real prosecution of the case against President Donald Trump will not begin in earnest until next week.

That's because the next 48 hours are a somewhat scripted affair that will include some pomp and circumstance and then all sides agree that members of the Senate will go home for a long weekend over the Martin Luther King Jr. holiday and resume the more substantive portion of the case next week.

The action begins Wednesday morning with House Speaker Nancy Pelosi, D-Calif., announcing her team of impeachment managers, members of the House who will prosecute the case in the Senate.

A vote later Wednesday will formally transmit the two articles of impeachment to the Senate, a procession that will come almost exactly four weeks after the House first voted to impeach Trump over his pressure on Ukraine to investigate potential presidential rival Joe Biden.

Pelosi's impeachment managers will line up and bring the articles across the Capitol and into the Senate chamber. "Either take your seats or go to the cloakrooms," Sen. Strom Thurmond, R-S.C.),said on Jan. 7, 1999, banging a gavel to tell senators to make way for the House managers.

Thurmond, who retired in 2003 and died soon after leaving office, served as the Senate's president pro tempore, ordering the managers to follow behind James Ziglar, the Senate's sergeant-at-arms at the time.

"Hear ye, hear ye, hear ye, all persons are commanded to keep silent, on pain of imprisonment, while the House of Representatives is exhibiting to the Senate of the United States articles of impeachment," Ziglar announced.

Sen. Chuck Grassley, R-Iowa, and Michael C. Stenger have those roles today, and once those formalities are taken care of, the lead prosecutor from the House will read the text of the impeachment charges against Trump.

Pelosi and Senate Majority Leader Mitch McConnell, R-Ky., have not done much coordinating on precise timing, as they have been feuding over the scope of the trial. Word late Tuesday was that the House managers would arrive Wednesday evening.

Once that occurs, the Senate will make final preparations for both the logistics of preparing the chamber - such as where to set up tables for the House members to sit - and notify Chief Justice John G. Roberts Jr. to make his way from the Supreme Court.

Back in 1999, then-Chief Justice William Rehnquist arrived promptly at 1 p.m., a little less than three hours after the Republican House managers read their impeachment charges to the Senate.

After House Democrats arrive late Wednesday, Senate Republicans expect Roberts to come Thursday afternoon.

This is where things will wrap up for the week.

"At that point the president pro tempore of the Senate would swear in the chief justice for his unique responsibilities here, and then the chief justice would swear all of us in. And we believe that's sort of the end of this week, once that occurs," Sen. Roy Blunt, R-Mo., chairman of the Senate Rules Committee, told reporters Tuesday.

This gap, if it occurs, puts off the more critical vote on the resolution governing the trial until Tuesday, but it's a delay that both sides favor. Four Senate Democrats are running for their party's presidential nomination and the coming weekend will be their last burst of activity over several days on the ground in Iowa and possibly New Hampshire, before those states' critical first caucus and first primary, respectively.

And Republicans will use the long weekend as one last respite for a trial that will run six days a week, beginning sharply at 1 p.m., with Sunday as their day off.

The Senate would convene Tuesday at 1 p.m. and hold a series of votes on the trial resolution. Democrats will be able to offer some preliminary amendments to the McConnell resolution on Tuesday, but they are vowing to be dignified and not look as if they are trying to stonewall the trial's start.

"This is not going to look like the House committee hearings. So I don't think there is going to be any danger that this comes off looking like a political circus," Sen. Chris Murphy, D-Conn., said in an interview.

All 53 Republicans have said they will oppose voting on witnesses until after the two legal teams present their cases, modeling their plan on President Bill Clinton's trial.

That plan would allow for the House managers to present their case in a 24-hour period stretched over three or four days, followed by Trump's legal team getting the same amount of time to rebut the House impeachment.

Then senators could write questions and send them to the chief justice to read them to the legal teams.

At that point senators would debate - all deliberations are done privately with no cameras or transcripts - and then hold public votes on whether to call witnesses, which has been a central demand from Democrats who want to hear from at least a quartet of Trump's inner circle of advisers.

Blunt estimated that the Pelosi-McConnell standoff, delaying the formal launch of the trial by more than a week, has made it "hard to imagine" that the case can be resolved before Trump delivers the State of the Union address the night of Feb. 4.

"You know, if we'd have gotten started properly, we might have," Blunt said.

It all starts in the next 48 hours, when House Democrats march across the Capitol with the articles, 21 years after Henry Hyde (R-Ill.), the late chairman of the House Judiciary Committee, led 12 other managers in a two-minute walk to the Senate's back door.

Hyde, who retired in 2007 and died a few months after leaving office, took less than 10 minutes to read the requisite resolutions.

"The managers now request leave to withdraw," Hyde said.

“Thank you, Mr. Manager Hyde,” Thurmond said. “The Senate will notify the House of Representatives when it is ready to proceed.”