In spite of Princess Diana’s divorce from Prince Charles, the royal maintained a strong relationship with Queen Elizabeth in the years before her tragic death. In fact, Lady Di had a special nickname for the 94-year-old monarch that’s so personal, it’s not even used by Kate Middleton.
During the last ten years of her life, Princess Diana reportedly called her mother-in-law “Mama,” according to Good Housekeeping. Although she separated from Prince Charles in 1992 and they later divorced in 1996, the royal leaned on the queen for support during the transition. At one point, Diana called Queen Elizabeth “sobbing,” as we learned in the 2017 documentary Diana: In Her Own Words.
It’s because of this close-knit bond that Queen Elizabeth allowed Princess Diana to call her “Mama.”
The moniker might surprise some royal aficionados, since members of the family aren’t supposed to use informal nicknames around the queen. For example, newcomers (like Meghan Markle) are expected to use “Your Majesty” until he/she establishes a personal relationship with the monarch. Only then can they graduate on to something like “Ma’am.”