President-elect Donald Trump has named Susie Wiles, the manager of his victorious campaign, as his White House chief of staff, the first woman to hold the influential role.

Wiles is widely credited within and outside Trump’s inner circle for running what was, by far, his most disciplined and well-executed campaign, and was seen as the leading contender for the position. She largely avoided the spotlight, even refusing to take the mic to speak as Trump celebrated his victory early Wednesday morning.

Wiles’ hire is Trump’s first major decision as president-elect and one that could be a defining test of his incoming administration, as he must quickly build the team that will help run the massive federal government. Wiles doesn’t bring government experience to the role, but has a close relationship with the president-elect.

She was able to do what few others have been able to: help control Trump’s impulses — not by chiding him or lecturing, but by earning his respect and showing him that he was better off when he followed her advice than flouting it.

“Susie is tough, smart, innovative, and is universally admired and respected. Susie will continue to work tirelessly to Make America Great Again,” Trump said in a statement. “It is a well deserved honor to have Susie as the first-ever female Chief of Staff in United States history. I have no doubt that she will make our country proud.”

Trump went through four chiefs of staff — including one who served in an acting capacity for a year — during his first administration, part of record-setting personnel churn in his administration.

Successful chiefs of staff serve as the president’s confidant, help execute a president’s agenda and balance competing political and policy priorities. They also tend to serve as a gatekeeper, helping determine whom the president spends his time with and whom he speaks to — an effort Trump chafed under inside the White House.

The chief of staff is “absolutely critical to an effective White House,” said Chris Whipple, whose book “The Gatekeepers” details how the White House chief of staff role shapes and defines a presidency. “At the end of the day the most important thing is telling the president what he doesn’t want to hear.”

“On the plus side, she’s shown that she can manage Trump, that she works with him and can sometimes tell him hard truths, and that’s really important,” said Whipple. “On the minus side, she really has no White House experience and hasn’t really worked in Washington in 40 years. And that’s a real disadvantage.”

Wiles is a longtime Florida-based Republican strategist who ran Trump’s campaigns in the state in 2016 and 2020. Before that, she ran Rick Scott’s 2010 campaign for Florida governor and briefly served as the manager of former Utah Gov. Jon Huntsman’s 2012 presidential campaign.

Chris LaCivita, who along with Wiles served as a co-manager of the campaign, posted on X, “So Happy and proud of one of the fiercest and most loyal warriors i’ve ever had the pleasure of working with !!!”

Trump often referenced Wiles on the campaign trail, publicly praising her leadership of what he said he was often told was his “best-run campaign.”

“She’s incredible. Incredible,” he said at a Milwaukee rally earlier this month,

At a rally in Pennsylvania where Trump made one of his last appearances before the election, he launched into a profane and conspiracy-laden speech. Wiles was spotted standing offstage and appearing to glare at him.

Later, at a rally in Pittsburgh, Trump seemed to acknowledge his adviser’s’ efforts to keep him on message.

After complaining that men aren’t allowed to call a woman “beautiful” any longer, he asked if he could strike that word from the record. “I’m allowed to do that, aren’t I, Susan Wiles?” he mused.