The controversy surrounding former national security adviser Michael Flynn has engulfed President Donald Trump’s White House. And yet it is Trump’s own staunch defense of Flynn that has fanned the intrigue.

Flynn was fired after just 24 days on the job after it was revealed he discussed sanctions against Russia with its ambassador to the U.S., Sergey Kislyak, before Trump’s inauguration and then repeatedly lied about doing so.

Yet Flynn has remained in the spotlight as the FBI investigates his ties to the Russian government as well as his lobbying on behalf of the Turkish government during Trump’s campaign.

But Flynn has also received a great deal of attention over Trump’s unusual devotion to him. Even though he fired him, Trump has continued to heap praise on the retired lieutenant general, has defended his communications with Russia and possibly attempted to obstruct justice in order to clear his former adviser’s name.

Few other Trump associates have received this kind of backing. His team has sought to distance the president from other ex-staffers under FBI investigation, including Trump’s former campaign manager Paul Manafort and his onetime foreign policy adviser Carter Page. In March, White House press secretary Sean Spicer claimed Manafort played a “very limited role for a very limited amount of time” in Trump’s presidential campaign. (Manafort managed the campaign from March to August 2016.) The same week, White House counselor Kellyanne Conway claimed the president didn’t know Page, despite the work he did on the presidential campaign.

With Flynn, it’s a different story.

According to a New York Times report, the White House knew Flynn was under investigation for his work with the Turkish government weeks before the inauguration. Trump still named him national security adviser, giving him access to the highest levels of classified information. The president also ignored a warning from President Barack Obama, who shortly after the election cautioned Trump against hiring Flynn. (Obama fired Flynn from his post at the Defense Intelligence Agency in 2014.)

And, according to the Daily Beast, Trump actually talked Flynn into taking the job even though Flynn was “reluctant.”

A week after the inauguration, then-acting Attorney General Sally Yates warned the administration that Flynn was “compromised” and “could essentially be blackmailed” by the Russian government. However, Flynn wasn’t fired until 18 days later.

Even after Flynn’s Feb. 13 dismissal, Trump maintained that Flynn did nothing wrong by speaking to Kislyak, claiming he fired Flynn only because he lied to Vice President Mike Pence about his Russian communications. He also described Flynn as a “wonderful man” who was “treated very, very unfairly by the media.”

Most notably, the president reportedly asked then-FBI Director James Comey on Feb. 14 to drop his investigation of Flynn. “He is a good guy,” Trump reportedly told Comey. “I hope you can let this go.”

The revelation, which emerged after Trump fired Comey on May 9, has thrown the White House into further chaos and has sparked discussion of impeachment.

Trump reportedly told Flynn last month to “stay strong” amid his growing legal woes.

So why would Trump potentially risk his own presidency to defend Flynn?

One possible explanation is Flynn’s fierce devotion to the president.

Loyalty, while not a virtue he seems to practice often himself, is one of the qualities Trump admires most in others. And Flynn had been one of Trump’s most loyal allies.

Flynn joined the campaign relatively early in the Republican primary, in February 2016, while most of the Republican Party was siding with candidates such as Sens. Ted Cruz and Marco Rubio. He was a frequent presence on the campaign trail and famously led the Republican National Convention in chants of “Lock her up!” in reference to Trump’s Democratic rival Hillary Clinton. While the GOP national security establishment lined up against Trump, Flynn advised his campaign on how to improve its foreign policy message and touted that message on cable news. And he stood by Trump during the fallout from the 2005 “Access Hollywood” tape, in which Trump boasted of sexual improprieties, even as many Republicans (at least temporarily) retracted their endorsements of him.

There’s been some speculation that Flynn must have some dirt on the president.

Wait. What if Mike Flynn has the pee tape? — Josh Barro (@jbarro) May 18, 2017

Joking aside, that speculation kicked into high gear after Flynn sought immunity in exchange for testifying in front of Congress and the FBI, an offer that was refused. But according to a report in Yahoo News, people close to Flynn say that his loyalty has not wavered and that the retired general has no plans to turn on Trump.

“These are two men who bonded on the campaign trail,” a Flynn associate told Yahoo. “Flynn always believed that Trump would win. They were together so much during the campaign that Flynn became family. There has been zero sign of anything but supreme loyalty.”

A White House official echoed that sentiment to The Atlantic:

“They got so close during the campaign,” said a senior White House official who was brought on by Flynn and has stayed after his departure. When Flynn left, “the real person who probably took it hardest was the president because General Flynn was the person closest to him on national-security matters.”

That loyalty has strained Trump’s relationship with Flynn’s replacement, Lt. Gen. H.R. McMaster, Politico reported. According to its sources, Trump “misses his conversations with Flynn” and is “struggling to connect” with his new national security adviser.