McDonald’s has fired President and CEO Steve Easterbrook after learning of a recent relationship he had with an employee, swiftly replacing him with McDonald’s U.S. president Chris Kempczinski.

Easterbrook “has separated from the company” after the board determined that he “violated company policy and demonstrated poor judgment involving a recent consensual relationship with an employee,” McDonald’s said in a statement on Sunday afternoon.

Easterbrook, in an email sent to McDonald’s employees, acknowledged the relationship and that it violated company policy. “This was a mistake. Given the values of the Company, I agree with the Board that it is time for me to move on. Beyond this, I hope you can respect my desire to maintain my privacy,” he wrote in the email.

Easterbrook had been McDonald’s president and CEO since March 2015 after serving as its chief brand officer. Now it is up to Kempczinski, who has been with McDonald’s just four years, to keep the turnaround rolling at the world’s largest restaurant company. Joe Erlinger, McDonald’s president of international operated markets, was named the president of McDonald’s U.S. business, taking that role from Kempczinski effective immediately.

Easterbrook had overseen a variety of changes at the fast feeder including the introductions of all-day breakfast, fresh beef quarter pounder patties and delivery in the U.S., areas in which Kempczinski has also been a key leader. Third-quarter sales were strong, with U.S. same-store sales up 4.8 percent and global comparable sales up 5.9 percent. Still, visits to McDonald’s longstanding U.S. locations remain in negative territory, a continued issue of stress for the company and its franchisees, who need to see visits tick up for stronger sustained growth.

A comment from Kempczinski included in the McDonald’s statement made sure to mention the partners he and other McDonald’s executives are working to improve relationships with, including its franchisees, who have been pushing for more of a say in the company’s decision-making.

“I’m thrilled to be leading this incredible company,” Kempczinski said. “Working alongside our talented team, our board, our franchisees and suppliers, I am committed to upholding our rich heritage of serving our customers and driving value for our shareholders and other stakeholders.”

In an email to employees, Kempczinski also discussed the importance of what McDonald’s refers to as a three-legged stool of the company, franchisees and suppliers. He also thanked Easterbrook.

“Steve brought me into McDonald’s and he was a patient and helpful mentor,” Kempczinski said in the email. “I wish him all the best in his future endeavors.” 

Easterbrook’s departure was briefly addressed in the company’s statement, which went on to detail the myriad reasons it plucked Kempczinski for the elevated role.

“In particular, Chris was instrumental in the development of the company’s strategic plan, which has enabled global growth and leadership, and has overseen the most comprehensive transformation of the U.S. business in McDonald’s history," Enrique Hernandez Jr., chairman of McDonald’s board, said in the company’s statement.

McDonald’s is in a much better position now than it was in 2015 when Easterbrook took over from Don Thompson amid weak results, and when Easterbrook hired Kempczinski as executive VP of strategy, business development and innovation. Kempczinski, who was previously at Kraft Heinz, joined McDonald’s in 2015 in the executive VP role and became president of McDonald’s U.S. business at the beginning of 2017.

Easterbrook’s departure is the latest in a series of C-level exits at the Golden Arches. Chief Marketing Officer Silvia Lagnado announced in July that she’d be leaving in October, and then Chief Communications Officer Robert Gibbs departed.