Mary Rhys-Jones (nee O'Sullivan), wife of Christopher Rhys Jones, and mother of HRH The Countess of Wessex, died 28 August, 2005. She was aged 71.
Mary Rhys Jones was the mother of Sophie Helen (b. 1965) who married the third son of Queen Elizabeth II in June, 1999.
Mrs Rhys Jones died on Sunday after a short illness at a hospital, a Buckingham Palace spokesman said in a brief statement, adding that the Countess of Wessex was at her mother's bedside.
"The countess was at the hospital and is deeply saddened by the news," a palace spokeswoman said.
A private funeral service and thanksgiving service was being planned, but details were not immediately available.
Mrs Rhys-Jones also leaves a son David (b. 1963), a daughter-in-law, Zara, and three grandchildren, Oliver Hugh Rhys-Jones (b. 1999), Harry Christopher Rhys-Jones (b. 2000), and Lady Louise Windsor (b. 2003).
Mrs Rhys Jones's husband is descended from the Viscounts Molesworth.