To commemorate his 42nd birthday, Charles took his two eldest children, Prince George and Princess Charlotte, to Wembley Stadium in London to attend the Eras Tour. (According to Town & Country, Kate Middleton stayed at home with Prince Louis.) During the evening, the royals visited Taylor Swift backstage and exchanged photographs with the pop sensation.

The Prince and Princess of Wales’ official social media accounts posted a photo of Swift taking a picture with the royals. “Thank you, @taylorswift, for a wonderful evening! #LondonTSTheErastour,” they wrote in the caption.

Swift shared a selfie from a slightly different position, with her boyfriend, Travis Kelce, wearing a Team USA Olympics hat. “Happy Bday M8!” Swift added in the caption, referring to Prince William’s birthday: “London shows are off to a splendid start.” She finished with emojis of the UK flag, the American flag, and a handshake.

Zara Tindall and her daughter, Mia Tindall, appear to have attended the concert alongside the Waleses, according to videos of the royals. The royals watched from a luxury box at Wembley Stadium, rather than the “VIP Tent” on the floor. The Prince of Wales is also seen dancing to “Shake It Off” during the 1989 segment of the show.

Swift is scheduled to perform seven more times at Wembley Stadium (two this month and five in London). The first night was incredibly star-studded—in addition to Prince William, Prince George, and Princess Charlotte, Bridgerton’s Nicola Coughlan, Cara Delevigne, Salma Hayek, and others were in attendance—so we can expect to see more celebs (and possibly more royals!) at her future events.