Queen Elizabeth Meets Kate Middleton's Parents
04/20/2011 AT 11:35 AM EDT
Despite reports that said they might not all meet until the April 29 wedding, the Queen, 85 tomorrow, and her husband, Prince Philip, 89, invited Michael, 61, and Carole Middleton, 56, to dine at Windsor Castle.
There are scant details available, but a royal source says there was a "warm atmosphere" at the gathering, which also included members of the royal household, some of whom have no doubt been involved behind-the-scenes in the upcoming wedding.
It is the first time they have formally met, although the Middletons would have seen William's grandmother among the parents and grandparents celebrating at the couple's graduation from St. Andrews University in 2005. The Middletons and the Queen and Prince Philip were also at the military academy of Sandhurst when William left there in December 2006.