Arab nations colloquially referred to Black September after King Hussein's 1970 crackdown on the PLO because of the brutality of the three-week war, which put an end to the PLO's rogue state-within-a-state in Jordan as well as its guerilla attacks on Israeli-occupied Arab territory in the West Bank. Hussein, who was the target of numerous assassination attempts by the PLO and other Palestinian factions, and whose authority had been in doubt, first signed a cease-fire agreement with the PLO in late September, 1970, then expelled Yasser Arafat and the PLO in early 1971. The PLO migrated to Lebanon, weapons and destabilizing designs in tow.
Black September, the movement, was created by a breakaway Palestinian faction of Fatah to avenge the loss of Jordan and more direcly target Israelis by terrorist means. On Nov. 28, 1971, Black September assassinated Jordanian Prime Minister Wasfi al-Tel while he was on an official visit in Cairo. The group targeted the Jordanian ambassador to Britain the following month. But its most notorious attack was the murder of 11 Israeli athletes at the Munich Olympics in September 1972.
Israel, in turn, launched an assassination squad to target members of Black September. It killed several of them, but also killed innocent people through 1973 in Europe and the Middle East.