King Hussein of Jordan declares war against the Palestine Liberation Organization, the conflict came to be known as Black September.

Hussein bin Talal was King of Jordan from 1952 until his death in 1999. As a member of the Hashemite dynasty, the royal family of Jordan since 1921, Hussein was traditionally considered a 40th-generation direct descendant of the Islamic prophet Muhammad.

Jordan, officially the Hashemite Kingdom of Jordan, is a country in the Southern Levant region of West Asia. Jordan is bordered by Syria to the north, Iraq to the east, Saudi Arabia to the south, and Israel and the occupied Palestinian territories to the west. The Jordan River, flowing into the Dead Sea, is located along the country's western border within the Jordan Rift Valley. Jordan has a small coastline along the Red Sea in its southwest, separated by the Gulf of Aqaba from Egypt. Amman is the country's capital and largest city, as well as the most populous city in the Levant.

The Palestine Liberation Organization is a Palestinian nationalist coalition that is internationally recognized as the official representative of the Palestinian people in both the occupied Palestinian territories and the diaspora. It is currently represented by the Palestinian Authority based in the West Bank city of Al-Bireh.

Black September, also known as the Jordanian Civil War, was an armed conflict between Jordan, led by King Hussein, and the Palestine Liberation Organization (PLO), led by chairman Yasser Arafat. The main phase of the fighting took place between 16 and 27 September 1970, though certain aspects of the conflict continued until 17 July 1971.