Watching the US singer perform at Wembley Stadium, the future king was also spotted shaking his arms to Shake It Off as he celebrated his 42nd birthday.

"Thank you Taylor Swift for a great evening," Prince William wrote on Instagram.

Swift posted her selfie with William, George and Charlotte alongside her boyfriend, NFL star Travis Kelce.

"Happy Bday M8," Swift wrote on Instagram. "London shows are off to a splendid start."

William's cousin Zara Tindall and her husband Mike Tindall were among the star-studded crowd, which reportedly included Bridgerton star Nicola Coughlan and model Cara Delevingne.

Labour leader Sir Keir Starmer was also present as he took time off from the campaign trail to attend the first night of the London leg of Swift's record-breaking Eras tour.

Prince William previously shared the stage with Swift and Jon Bon Jovi for a performance of Livin' On A Prayer for a charity event at Kensington Palace in 2013.

Swift is performing three gigs at the 90,000-capacity London venue this weekend - on Friday, Saturday and Sunday - before returning to the venue for a further five in August.

London has been overtaken with Taylor-mania in recent days, with the city's iconic Tube map redrawn to celebrate her arrival.

Her hit Shake It Off was also played at the traditional Changing of the Guard ceremony at Buckingham Palace on Friday.

On Thursday it was revealed that Swift's fans were expected to boost the London economy by £300m as the capital hosts more Eras Tour shows than any other city in the world, with nearly 640,000 people expected to attend across the eight dates.