former consort (1981–96) of Charles, prince of Wales, and mother of the heir second in line to the British throne, Prince William, duke of Cambridge (born 1982).

Diana was born at Park House, the home that her parents rented on Queen Elizabeth II's estate at Sandringham and where her childhood playmates were the queen's younger sons, Prince Andrew and Prince Edward. She was the third child and youngest daughter of Edward John Spencer, Viscount Althorp, heir to the 7th Earl Spencer, and his first wife, Frances Ruth Burke Roche (daughter of the 4th Baron Fermoy). She became Lady Diana Spencer when her father succeeded to the earldom in 1975. Riddlesworth Hall (near Thetford, Norfolk) and West Heath School (Sevenoaks, Kent) provided the young Diana's schooling. After attending the finishing school of Chateau d'Oex at Montreux, Switzerland, Diana returned to England and became a kindergarten teacher at the fashionable Young England school in Pimlico.

She renewed her contacts with the royal family, and her friendship with Charles grew in 1980. On February 24, 1981, their engagement was announced, and on July 29, 1981, they were married in St. Paul's Cathedral in a globally televised ceremony watched by an audience numbering in the hundreds of millions. Their first child, Prince William Arthur Philip Louis of Wales, was born on June 21, 1982, and their second, Prince Henry Charles Albert David, on September 15, 1984. Marital difficulties led to a separation between Diana and Charles in 1992, though they continued to carry out their royal duties and jointly participate in raising their two children. They divorced on August 28, 1996, with Diana receiving a substantial settlement.

After the divorce, Diana maintained her high public profile and continued many of the activities she had earlier undertaken on behalf of charities, supporting causes as diverse as the arts, children's issues, and AIDS patients. She also was involved in efforts to ban land mines. Her unprecedented popularity as a member of the royal family, both in Britain and throughout the world, attracted considerable attention from the press, and she became one of the most-photographed women in the world. Although she used that celebrity to great effect in promoting her charitable work, the media (in particular the aggressive freelance photographers known as paparazzi) were often intrusive. It was while attempting to evade journalists that Diana was killed, along with her companion, Dodi Fayed, and their driver, in an automobile accident in a tunnel under the streets of Paris.

Though the photographers were initially blamed for causing the accident, a French judge in 1999 cleared them of any wrongdoing, instead faulting the driver, who was found to have had a blood-alcohol level over the legal limit at the time of the crash and to have taken prescription drugs incompatible with alcohol. In 2006 a Scotland Yard inquiry into the incident also concluded that the driver was at fault. In April 2008, however, a British inquest jury ruled both the driver and the paparazzi guilty of unlawful killing through grossly negligent driving, though it found no evidence of a conspiracy to kill Diana or Fayed, an accusation long made by Fayed's father.

Her death and funeral produced unprecedented expressions of public mourning, testifying to her enormous hold on the British national psyche. Her life, and her death, polarized national feeling about the existing system of monarchy (and, in a sense, about the British identity), which appeared antiquated and unfeeling in a populist age of media celebrity in which Diana herself was a central figure.