Royal expert Robert Jobson alleges that Katy Perry "caused a stir" among the royal family when she performed at King Charles III's coronation in May 2023. In The Windsor Legacy, which is set to be released next year, Jobson recounted the "star-studded" Coronation Concert that took place the day after Charles' official coronation ceremony. (The king, 77, took the throne immediately following the September 2022 death of his mother, Queen Elizabeth II.