A civil war in Jordan from September 1970-July 1971, which began after several failed assassination attempts on the Jordanian king and the hijacking of three airplanes. The conflict centered on whether Jordan would be controlled by the Palestine
Liberation Organization (PLO) or the Hashemite monarchy. The Palestinian
population in Jordan at that time comprised 60% of the entire populace. Thousands (predominantly Palestinians) were killed. King Hussein and the Jordanian Armed Forces were backed by the United States and Israel
against the PLO, while Hussein's attacks on Palestinian fighters and civilians were seen as traitorous in the Arab world. The PLO leadership and thousands of Palestinian fighters were expelled from Jordan to Lebanon. The Black September Group, known best for its role in the murder of Israeli
athletes during the 1972 Summer Olympics in Munich, took its name from this event. See "1970: Civil war breaks out in Jordan
," BBC "On This Day," September 17, 1970.