Queen Elizabeth II will not attend the civil marriage ceremony of her son, Prince Charles, and his new bride, Camilla Parker Bowles on April 8, according to Buckingham Palace.
The palace said the queen would attend the church blessing afterwards and was happy to host the reception.
"The queen and the rest of the royal family will, of course, be going to the service of dedication at St George's Chapel, Windsor Castle," the spokeswoman said.
"The queen's prime concern is that the civil ceremony should be as low key as possible, in line with the couple's wishes."
Asked if this was a royal snub, she replied: "The queen is attending the service of dedication and paying for the reception. This is not a snub."
Prince William and Prince Harry, along with Parker Bowles' children, Tom and Laura, plan to attend the ceremony.
Prince Charles will also not have a best man at his wedding.
Heirs to the throne usually have two 'supporters', or best men, at the ceremony, but Prince Charles's spokesperson said, "It's not that sort of wedding."