Black September

In September 1970 the Jordanian army of King Hussein turned on the armed Palestinian groups of the Palestine Liberation Organization, led by Yasser Arafat, which had built a powerful presence inside the kingdom. The conflict, also called the Jordanian Civil War, saw its heaviest fighting between 16 and 27 September 1970, drew in a brief Syrian invasion, and ended in July 1971 with the guerrillas expelled from Jordan. It is best known by its Arabic name, Aylul al-Aswad, or Black September, after the month of the main fighting.

After annexing the West Bank in 1950, Jordan gave its Palestinian residents citizenship, and Palestinians came to form a large part of the kingdom's population. From 1965 the Palestinian movement Fatah launched raids into Israel, which brought heavy Israeli reprisals on Jordan. When Israel took the West Bank in the Six-Day War of 1967, the fedayeen, as the guerrillas were known, moved their bases to the East Bank.

On 21 March 1968 Israeli forces attacked the guerrilla headquarters at Karameh. The day-long battle, in which Jordanian troops also fought, brought a wave of Arab support and recruits to the PLO. Over the next two years the armed groups set up checkpoints, tried to levy their own "taxes" and came to be seen as a state within the state, while leftist factions such as the Popular Front for the Liberation of Palestine (PFLP) openly called for the overthrow of the Hashemite monarchy.

Hussein faced a dilemma: crushing the fedayeen risked alienating Palestinians and the Arab world, while inaction risked the loyalty of his army. In June 1970 clashes broke out in Zarqa and Amman, the king's motorcade was fired upon, and the PFLP held foreign hostages in Amman hotels. Ceasefires were signed in June and July but did not hold.

On 6 September, after renewed clashes in Amman, the PFLP hijacked three airliners, two of which landed at a desert airstrip in Jordan; a fourth was seized on 9 September. The hijackers demanded the release of prisoners held in Europe and Israel and, after removing the hostages, blew up the aircraft in front of the world's press on 12 September. For Hussein this was the final provocation.

On 16 September Hussein installed a military government and the next day his tanks entered Amman, shelling the fedayeen strongholds in the Wehdat and Hussein refugee camps, while other units attacked Irbid, Jerash, As-Salt and Zarqa.

On 18 September Syrian armoured forces bearing Palestine Liberation Army markings crossed into northern Jordan towards Irbid. Hussein sought outside help through Britain and the United States, and Israel made a show of readiness. On 22 September Jordanian aircraft and ground forces struck the Syrians, and the invaders withdrew that evening. Under pressure from Arab governments, Hussein accepted a ceasefire brokered by Egypt's Gamal Abdel Nasser at an emergency Arab summit in Cairo.

An agreement signed with Arafat in Amman on 13 October did not end the clashes. Under the new prime minister, Wasfi Tal, the army drove the fedayeen out of Irbid in March 1971, ordered their bases out of Amman in April, and in July encircled their last 2,000 fighters in the hills around Ajloun and Jerash. They surrendered and were allowed to leave for Syria, while some 200 chose to surrender to Israeli forces instead.

Estimates of Palestinian deaths vary widely, from 2,000 to 3,400 in most accounts, while Arafat claimed 25,000. The Jordanian army lost around 537 dead, and the Syrians lost about 120 tanks.

The PLO regrouped in southern Lebanon, where its presence added to the tensions that helped precipitate the Lebanese Civil War. A clandestine group calling itself the Black September Organization assassinated Wasfi Tal in Cairo on 28 November 1971 and later carried out the 1972 Munich attack on Israeli athletes. Although Jordanians and Palestinians fought on both sides in 1970, historians note that the conflict deepened a Jordanian–Palestinian divide in the years that followed.

Our 1960 map shows Jordan including the West Bank, and the 1985 map shows the kingdom after the loss of that territory, bordered by Syria to the north.