May 13, 1948

1948Kathleen Cavendish, Marchioness of Hartington (born 1920)^[†]

Kathleen Agnes Cavendish, Marchioness of Hartington, also known as "Kick" Kennedy, was an American socialite. She was the second daughter of Joseph P. Kennedy Sr. and Rose Fitzgerald, a sister of U.S. President John F. Kennedy and Senators Robert F. Kennedy and Ted Kennedy, and the wife of the Marquess of Hartington, heir apparent to the 10th Duke of Devonshire.

1948Arab–Israeli War: The Kfar Etzion massacre occurs, a day prior to the Israeli Declaration of Independence.^[†]

The 1948 Arab–Israeli War, also known as the First Arab–Israeli War, followed the civil war in Mandatory Palestine as the second and final stage of the 1948 Palestine war. The civil war became a war of separate states with the Israeli Declaration of Independence on 14 May 1948, the end of the British Mandate for Palestine at midnight, and the entry of a military coalition of Arab states into the territory of Mandatory Palestine the following morning. The war formally ended with the 1949 Armistice Agreements which established the Green Line.