Gordon Sondland, the U.S. ambassador to the European Union, testified Wednesday in what was the most anticipated public hearing yet in the House Democrats’ impeachment inquiry.

Sondland, a key figure in President Donald Trump’s dealings with Ukraine, shared new — and occasionally explosive — pieces of information, departing Capitol Hill after nearly seven hours in front of the House Intelligence Committee.

Later in the day, in an abbreviated public hearing, Laura Cooper, the top Pentagon official overseeing U.S. policy regarding Ukraine, and David Hale, undersecretary of state for political affairs, also testified.

Here's what we learned after another marathon day of hearings.

1. "We followed the president's orders" in pressuring Ukraine

Sondland directly pointed his finger at Trump, saying the president ordered that he, Kurt Volker, then-U.S. special envoy to Ukraine, and Energy Secretary Rick Perry work with the president's personal lawyer Rudy Giuliani on Ukraine policy, even though they were uncomfortable with Giuliani's role and associations.

“Secretary Perry, Ambassador Volker and I worked with Mr. Rudy Giuliani on Ukraine matters at the express direction of the president of the United States. We did not want to work with Mr. Giuliani. Simply put, we played the hand we were dealt. We all understood that if we refused to work with Mr. Giuliani, we would lose an important opportunity to cement relations between the United States and Ukraine. So we followed the president's orders,” he said.

Giuliani — Sondland and others testified — played a signature role in orchestrating an attempted quid pro quo with Ukraine. Sondland’s unequivocal description of Trump as the mastermind behind Giuliani’s prerogatives significantly advances House Democrats’ allegation that the attempted quid pro quo ultimately started in the Oval Office.

2. Sondland acknowledges direct line to Trump

Sondland also confirmed he'd held a July 26 phone call with Trump that only came to light last week when Bill Taylor, the top U.S. diplomat in Ukraine, testified that one of his staffers had overheard it. Taylor — as well as the staffer, David Holmes — testified that Trump asked Sondland on that call if Ukraine would investigate the Bidens and a conspiracy related to the 2016 election.

Sondland said Wednesday, "I have no reason to doubt that this conversation included the subject of investigations." He also said he did not disagree with the accounts of the calls provided by “other witnesses” — although he added that he had "no recollection of discussing Vice President Biden or his son on that call or after the call ended."

Sondland, who already corrected his prior closed-door testimony once before, had not previously revealed the existence of the call. His confirmation of it reveals that he had a direct line to Trump, as others testified, and is the first testimony directly tying the president to the effort of asking Ukraine to investigate the Bidens, other than the summary of the July 25 call between Trump and Ukrainian President Volodymyr Zelenskiy.

3. "Everyone was in the loop," including Pompeo, Bolton

In an especially explosive part of his opening statement, Sondland implicated Secretary of State Mike Pompeo, former national security adviser John Bolton and several other top officials in those two agencies.

Sondland said he’d made Pompeo and Bolton fully aware, at every turn, of what he, Volker and Perry were doing with regard to Ukraine policy at the direction of Giuliani.

And, he brought the emails — including direct responses from Pompeo — to prove it.

"We kept the leadership of the State Department and the NSC informed of our activities," he said, name-dropping Pompeo, Bolton, fellow inquiry witnesses Fiona Hill, Tim Morrison, and others. "They knew what we were doing and why."

“Everyone was in the loop. It was no secret," he added later.

Never before in the inquiry’s public hearings had it been made so clear how broadly known the administration’s dealings in question in Ukraine apparently were — and by such key policy makers.

Sondland testified that Pompeo, in fact, was still directing Volker to deal with Giuliani as recently as Sept. 24 — the day the White House released the summary of the July 25 call.

Furthermore, Sondland said, the fact that he had constantly kept the "decision-makers" at the NSC and State Department updated "of our efforts" actually proved that he, Volker and Perry were, in fact, not part of any shadow or parallel policy team, as other witnesses have alleged.

Rather, he said, "We were operating well within the center lane of U.S. diplomacy."

State Department spokesperson Morgan Ortagus said in a statement that Sondland "never told Secretary Pompeo that he believed the President was linking aid to investigations of political opponents" and that "any suggestions to the contrary is flat out false.”

4. Clear "quid pro quo" involving White House meeting, Sondland says

Sondland was unambiguous in saying that Trump, through Giuliani, attempted a quid pro quo under which a White House meeting for Zelenskiy was conditioned on Zelenskiy making a public statement announcing investigations into Burisma — the Ukrainian gas company that Hunter Biden joined as a board member in 2014 — and a conspiracy theory about Ukrainian interference in the 2016 election.

“I know that members of this committee have frequently framed these complicated issues in the form of a simple question: Was there a ‘quid pro quo?’ As I testified previously, with regard to the requested White House call and White House meeting, the answer is yes,” Sondland said.

“Mr. Giuliani conveyed to Secretary Perry, Ambassador Volker and others that President Trump wanted a public statement from President Zelenskiy committing to investigations of Burisma and the 2016 election. Mr. Giuliani expressed those requests directly to the Ukrainians. Mr. Giuliani also expressed those requests directly to us. We all understood that these prerequisites for the White House call and White House meeting reflected President Trump's desires and requirements,” he added.

Never before in the inquiry’s public hearings has this explicit arrangement been put so clearly. It is a central part of the case House Democrats are building and Sondland's testimony in support of it is deeply damaging to Republican counterarguments.

5. Alleged "quid pro quo" related to military aid was "my personal guess," Sondland says

Sondland, however, was less clear about whether Trump, through Giuliani, had conditioned the release of nearly $400 million in military aid to Ukraine on the public announcement of the desired investigations.

In his opening statement, Sondland said, despite having “tried diligently” to discover why the aid was suspended, he “never received a clear answer.”

"In the absence of any credible explanation for the suspension of aid, I later came to believe that the resumption of security aid would not occur until there was a public statement from Ukraine committing to the investigations of the 2016 election and Burisma, as Mr. Giuliani had demanded,” he said.

Under questioning from Intelligence Chairman Adam Schiff, Sondland said it was his “personal presumption, based on the facts at the time,” that he ultimately thought the military assistance to Ukraine was being withheld pending an announcement by Zelenskiy to open the sought-after investigations.

He appeared to soften that under questioning from Democratic staff attorney Daniel Goldman, saying a quid pro quo connected to "the aid was my own personal guess."

"My testimony is I never heard from President Trump that aid was conditioned on announcement" of the investigations into Burisma and the 2016 election.

Then, a moment later, Sondland said that "by Sept. 8" — the date of a text message exchange with Taylor — "I was absolutely convinced it was."

6. Sondland says he raised concerns about military aid freeze to Pence

Sondland said Wednesday he directly told Vice President Mike Pence of his concerns about a possible link between the release of military aid to Ukraine and the announcement of the investigations by Ukraine into Burisma Holdings and the 2016 election. He noted that this occurred when Pence was in Warsaw, Poland, for a Sept. 1 meeting with Zelenskiy. Sondland was there, as well.

"I mentioned to Vice President Pence before the meetings with the Ukrainians that I had concerns that the delay in aid had become tied to the issue of investigations. I recall mentioning that before the Zelenskiy meeting," Sondland testified. He added that Zelenskiy, during his meeting with Pence, "raised the issue of security assistance directly with Vice President Pence" and that Pence said "he would speak to President Trump about it."

Sondland's accusation about Pence puts the vice president squarely in the middle of the saga.

Pence, though his chief of staff Marc Short, denied having had this conversation with Sondland. It "never happened," Short said.

7. Ukrainians were aware of issues with aid earlier than previously known

Cooper testified that, in the weeks following her closed-door deposition and the release of the transcript of that deposition, her staff informed her of two emails her office had received on July 25 that strongly indicated the Ukrainians knew about the hold on military aid, or were at least asking questions about it.

Those emails — sent just hours after the call between Trump and Zelenskiy at the center of the impeachment inquiry — suggest that Zelenskiy may have known that the aid was held up, or that something was at least amiss, when he spoke with Trump on that same day.

The first email, Cooper said, showed that the “Ukrainian embassy and House Foreign Affairs Committee are asking about the security assistance,” and the second suggested that "the Hill knows" about a hold on the aid, "and so does the Ukrainian embassy," an apparent reference to Capitol Hill.

That the Ukrainians were aware of issues with the aid on the same day of the Trump-Zelenskiy call contradicts the argument by Republicans, including Trump, that a quid pro quo could have never been possible because the Ukrainians hadn’t known at the time of the call that the aid was being held.

Previous witnesses, including Taylor, have testified that Ukraine did not find out about the hold until August.

Hale, meanwhile, testified that a White House Office of Management and Budget official said at a July 26 interagency meeting that military aid was being held “because the president had so directed through the acting chief of staff," Mick Mulvaney.