They had a previously unannounced meeting at the White House in September 2019.

"Mark is in Washington, D.C., meeting with policymakers to hear their concerns and talk about future internet regulation. He also had a good, constructive meeting with President Trump at the White House today," a Meta spokesperson said at the time.

"‪Nice meeting with Mark Zuckerberg of Facebook in the Oval Office today," Trump said of their meeting.

Trump, Zuckerberg, and Peter Thiel had a secret dinner in October 2019.

Thiel, who cofounded PayPal and Palantir, was the first outside investor in Facebook; he was a vocal supporter of Trump in the 2016 presidential election.

"We talked about a number of things that were on his mind, and some of the topics that you read about in the news around our work," Zuckerberg said of the dinner in an interview with "CBS This Morning."

Zuckerberg was in DC to testify before Congress about Facebook's cryptocurrency, Libra.

In 2021, Trump praised Nigeria for banning Twitter.

"More COUNTRIES should ban Twitter and Facebook for not allowing free and open speech — all voices should be heard," Trump said in a statement at the time.

"Perhaps I should have done it while I was President," he added. "But Zuckerberg kept calling me and coming to the White House for dinner telling me how great I was."

Nigeria lifted its ban on Twitter after seven months.

In 2021, Meta "indefinitely" suspended Trump's accounts following the January 6 Capitol riots, citing "use of our platform to incite violent insurrection against a democratically elected government."

"His decision to use his platform to condone rather than condemn the actions of his supporters at the Capitol building has rightly disturbed people in the US and around the world," Zuckerberg wrote in a post at the time. "We removed these statements yesterday because we judged that their effect -- and likely their intent -- would be to provoke further violence."

In the time since the suspension, Facebook's Oversight Board examined the decision.

Eventually, Meta decided to reinstate Trump's account.

It did so while putting "new guardrails in place to deter repeat offenses," including bigger penalties for any violations of Meta's rules.

In July, Meta removed the additional guardrails that remained in place on Trump's Facebook and Instagram accounts following their reinstatement.

"In assessing our responsibility to allow political expression, we believe that the American people should be able to hear from the nominees for President on the same basis," Meta said in a statement at the time. "As a result, former President Trump, as the nominee of the Republican Party, will no longer be subject to the heightened suspension penalties."

Meta added that it would "review accounts subject to this protocol on a periodic basis to determine whether heightened suspension penalties for Community Standards violations remain appropriate."

"We should be suing Google and Facebook and all that," he said in a June 2019 interview with Fox Business. "Which, perhaps we will."

Trump made the remarks in the context of fines the European Union has levied against big tech firms like Google for breaching the bloc's antitrust rules.

Trump filed suit against Facebook, Google, Twitter, and the companies' respective CEOs in July 2021, alleging they unlawfully censor him and other conservatives.

In May 2022, Trump's lawsuit against Twitter was dismissed.

Zuckerberg expressed awe over Trump's response to getting shot.

"Seeing Donald Trump get up after getting shot in the face and pump his fist in the air with the American flag is one of the most badass things I've ever seen in my life," Zuckerberg told Bloomberg of the attempted Trump assassination. "On some level as an American, it's like hard to not get kind of emotional about that spirit and that fight, and I think that that's why a lot of people like the guy."

But the Meta CEO said he wasn't planning to endorse any candidate for president this election cycle.

When asked about the shooting, Meta AI, in some widely-circulated instances, claimed Trump wasn't shot.

"He actually apologized; he said they'd made a mistake," Trump said on "Mornings with Maria" on Fox Business. "He actually announced he's not going to support a Democrat because he can't because he respected me for what I did that day."

A spokesperson for Meta declined to comment but didn't dispute that the two had talked. The spokesperson also referred BI to Zuckerberg's statement last month that he wouldn't be endorsing any presidential candidate in 2024.

As for the Meta AI posts about the shooting, Meta said in a July blog post: "In both cases, our systems were working to protect the importance and gravity of this event. And while neither was the result of bias, it was unfortunate and we understand why it could leave people with that impression. That is why we are constantly working to make our products better and will continue to quickly address any issues as they arise."

In July, Trump said he'd pursue "Election Fraudsters" if re-elected and that they'd "be sent to prison for long periods of time."

"We already know who you are. DON'T DO IT! ZUCKERBUCKS, be careful!" Trump wrote on Truth Social at the time.

Zuckerberg and his wife, Priscilla Chan, donated roughly $400 million to nonprofits in 2020 to help state and local governments conduct a presidential election during an unprecedented pandemic. Republicans have remained furious over the donations. Meta has repeatedly tried to repair relationships, but many in the GOP remain incensed even though there's no evidence that the funds favored Democrats.

Amid continued criticism of his donations, Zuckerberg announced he would not make a similar contribution ahead of the 2024 election.

Politico reported that Trump included a picture of himself with the Meta CEO, with the caption, "He would bring his very nice wife to dinners, be as nice as anyone could be, while always plotting to install shameful Lock Boxes in a true PLOT AGAINST THE PRESIDENT."

It's unclear when Trump wrote the caption, though he appears to be referring to a $420 million contribution Zuckerberg and his wife made to fund election infrastructure in 2020.

While in office, Trump signed an executive order to ban TikTok, which President Biden revoked upon taking office after Trump.

Trump now views a TikTok ban differently.

"Now that I'm thinking about it, I'm for TikTok because you need competition," Trump told Bloomberg Businessweek in July. "If you don't have TikTok, you have Facebook and Instagram, and that's, you know, that's Zuckerberg."

In March, he made similar comments in an interview on CNBC's "Squawk Box" and referred to Facebook as "an enemy of the people."

"There's a lot of good and there's a lot of bad with TikTok," he said. "But the thing I don't like is that without TikTok, you can make Facebook bigger. And I consider Facebook to be an enemy of the people."

Like other major CEOs, Zuckerberg quickly praised Trump after it became apparent that the former president had won the 2024 election.

"Congratulations to President Trump on a decisive victory. We have great opportunities ahead of us as a country," Zuckerberg wrote on Threads on November 6. "Looking forward to working with you and your administration."

Zuckerberg was invited to dine with Trump on Thanksgiving eve, a Meta spokesperson said.

The Meta CEO traveled to Mar-a-Lago, Trump's Palm Beach club nicknamed "The Winter White House." Trump has been holding meetings there with potential cabinet picks and other top staffers as he prepares to retake the White House in January.

The New York Times reported that Zuckerberg "initiated" the meeting.

Some in Trump's orbit are taking notice of Zuckerberg's efforts.

"Mark Zuckerberg has been very clear about his desire to be a supporter of this and a participant in this change that we're seeing all around America, all around the world with this reform movement that Donald Trump is leading," longtime Trump advisor Stephen Miller, who will also return to the White House, told Fox News.

Miller cautioned "we'll see what comes" of Zuckerberg's rapprochement but made clear that the Meta CEO "understands" the change Trump is seeking.

On December 11, The Wall Street Journal reported that Meta had donated $1 million to Trump's inauguration fund, telling his campaign of the plan ahead of the dinner between the billionaires.