Princess Diana's father, the 8th Earl Spencer, died Sunday of a heart attack, a spokesman for Humana Wellington Hospital said. He was 68.
The princess and her husband, Prince Charles, heir to the British throne, were returning to London from a skiing vacation in Austria.
The day before she left for Austria, the princess and her eldest son, 9-year-old Prince William, visited the earl at the hospital where he was being treated for pneumonia.
Edward John Spencer suffered a stroke in 1978, which left him unsteady when he walked Diana down the aisle at St. Paul's Cathedral in 1981 for her marriage to Prince Charles.
In addition to Diana, the earl--known to friends as Johnnie--had a son, Charles, Viscount Althorp, and daughters Lady Sarah McCorquodale and Lady Jane Fellowes.
The earl was divorced in 1969 from the former Frances Roche, mother of his four children. He remarried in 1976, to Raine Legge, whose mother is the best-selling romance novelist Dame Barbara Cartland.
Spencer, who succeeded his father on the 7th earl's death in 1975, was educated at Eton and at Sandhurst military college.
In 1947, he served as aide to the governor of South Australia. In 1950, he became an equerry (attendant) to King George VI and then to Queen Elizabeth II for two years until 1954. He was earlier commissioned in the Royal Scots Greys regiment.