When Kate Middleton married Prince William at Westminster Abbey fifteen years ago, the late Queen Elizabeth II bestowed special new titles to the newlyweds: The Duke and Duchess of Cambridge, Earl and Countess of Strathearn, and Baron and Baronness of Carrickfergus. A new royal biography claims that Prince Charles and Queen Camilla also requested an unusual name change when Princess Kate joined the family, which Prince Harry mentioned in his memoir, Spare , three years ago. Prince William and Kate Middleton at their wedding. (Image credit: Getty Images) Christopher Andersen Kate!: the Courage, Grace, and Power of the Woman Who Will Be Queen The newly-titled Duke and Duchess of Cambridge. (Image credit: Getty/Peter Macdiarmid) According to royal biographer Christopher Andersen, author of the upcoming book Kate!…