Wedding of Kathleen Kennedy and William Cavendish, 6th May 1944 (b/w photo)

Kathleen Agnes Cavendish, Marchioness of Hartington (née Kennedy; February 20, 1920 – May 13, 1948) was an American socialite. She was the fourth child and second daughter of Joseph P. Kennedy, Sr. (1888–1969) and Rose Fitzgerald (1890–1995). She was a sister of future U.S. President John F. Kennedy (1917–1963) and wife of William Cavendish, Marquess of Hartington, a soldier and politician. William John Robert "Billy" Cavendish, Marquess of Hartington (10 December 1917 – 10 September 1944), was an English politician and soldier. He was the eldest son of Edward Cavendish, 10th Duke of Devonshire, and his wife, Lady Mary Gascoyne-Cecil. He was the husband of Kathleen Kennedy, sister of the future U.S. President John F. Kennedy