President Obama's Long History of Insulting Donald Trump The two are set to meet at the White House today.

 -- Barack Obama and Donald Trump had never been introduced before their meeting at the White House today, but that hasn't stopped the pair from trading insults for years.

The president and the president-elect are expected to put on a very civil display today at the White House after Trump's surprising electoral victory on Tuesday night, and that comes as quite the turn from their previous treatment of each other.

Trump insulted Obama throughout the presidential campaign. However, a certain degree of criticism from a candidate is expected when he's trying to take over the incumbent's spot.

But their back-and-forth dates back years before Trump publicly announced his plans to run for the White House in 2015.

The tension largely stems from Trump's dogged pursuit of the so-called birther theory. He regularly and publicly questioned where Obama was born and whether he was a legitimate U.S. citizen.

Trump's questioning started around 2011 and ultimately led Obama to release the long-form version of his Hawaiian birth certificate. That then launched a string of appearances where Obama took the opportunity to insult Trump.

The first came without Obama's naming Trump: When Obama announced the release of the long-form certificate in April 2011, he blamed the distractions raised "by sideshows and carnival barkers" as taking focus away from important issues.

Three days later, Obama took his criticism of Trump to a higher level of roast at the White House Correspondents' Association Dinner. With Trump in attendance, Obama needled him on the issue by walking out to Rick Derringer's "Real American" and later "revealing" his "long-form birth video," which ended up being a clip from "The Lion King."

Obama noted that Trump was in the room and then went after him. "I know that he's taken some flak lately, but no one is happier, no one is prouder to put this birth certificate issue to rest, and that's because he can finally get back to focusing on the issues that matter, like did we fake the moon landing? What really happened in Roswell? And where are Biggie and Tupac?" Obama said.

He then teased Trump about his "credentials and breadth of experience" by citing a tough decision that Trump had to make on a then-recent episode of "The Apprentice" that involved firing actor Gary Busey.

Obama even pointed to a mock-up picture of what the White House could look like if Trump ever became president — with an added high-rise, a neon sign with Trump's name on the facade and a whole lot more gold.

The digs prompted big laughs in the ballroom, and though the room was dark, the cameras regularly panned back to Trump, who sat stiffly through the whole thing, at times with a forced smile on his face.

The edgy insults didn't stop in 2011. When Trump — seemingly unconvinced by Obama's birth certificate — released a video in 2012 saying he would pay $5 million to a charity of the president's choice if he released a copy of his passport and his college transcripts, Obama responded with humor again.

"This all dates back to when we were growing up together in Kenya," Obama joked during an appearance on "The Tonight Show."

"We had, you know, constant run-ins on the soccer field. He wasn't very good, resented it. When we finally moved to America, I thought it would be over." (In September, after years of attacks, Trump finally acknowledged that Obama was in fact born in the U.S.)

Obama's criticisms of Trump became more pointed and political during the 2016 presidential campaign, some of which came in recent weeks.

In early October, after the release of a 2005 "Access Hollywood" recording of Trump making vulgar remarks about women, Obama questioned the Republican nominee's character and apparent tendency to lash out.

"One of the most disturbing things about this election is just the unbelievable rhetoric coming from the top of the Republican ticket. I don't need to repeat it — there are children in the room," Obama said at a news conference in Chicago.

"It tells you he's insecure enough that he pumps himself up by putting others down — not a character trait that I would advise in the Oval Office. It tells you that he doesn't care very much about the basic values we try and impart to our kids. It tells you that he'd be careless with civility and the respect that a real vibrant democracy requires," he continued.

Obama also regularly questioned Trump's capacity to lead during his campaign appearances for Hillary Clinton, occasionally throwing in lighthearted insults as well, up to just before the election.

"In the last two days, they had so little confidence in his self-control, they said, 'We're just going to take away your Twitter,'" Obama said on Sunday, referring to a New York Times report that came out hours before that said Trump's campaign staffers kept him from tweeting directly. "Now, if somebody can't handle a Twitter account, they can't handle the nuclear codes."