It has its roots in the migration of more than half a million Palestinian refugees to Transjordan as a result of the 1948 Arab-Israeli War. King Abdullah of Jordan, after the annexation of the West Bank in the same year, resettled enough Palestinians on his land, corresponding to two-thirds of the total Jordanian population. This event set the stage for future conflicts between the politicized discontented Palestinians and the Jordanian monarchy. The events began on September 7, 1970, when the Palestine Liberation Front (PFLP), the second largest faction of the Palestine Liberation Organization (PLO), hijacked four civilian planes and detonated the planes immediately after dropping all the passengers after landing three of them on Jordanian soil. King Hussein, seeing the kidnappings as a direct threat to his authority, declared martial law on September 16 and ordered the PFLP militants to lay down their arms. That same day, Yasser Arafat became commander-in-chief of the PLO's regular military arm, the Palestine Liberation Army (PLA). In the next ten days, a very bloody civil war took place between the PLA and the Jordanian army, and Syria sent support to the PLA. With the US navy and Israel making "precautionary military deployments" in Jordan to assist King Hussein, Syrian forces began to withdraw on September 24 and a ceasefire was concluded with the PLA on September 25. Three days later, King Hussein and Arafat met in Cairo and signed an agreement that would move the guerrillas to suitable locations to continue the war with Israel. Although it is estimated that around 3,400 Palestinians lost their lives in the conflicts during this period, Arafat claimed that approximately 20,000 people died.
Sources: Kristian Patrick Alexander – Black September, John K. Cooley – Green March, Black September: The Story of Palestinian Arabs
It is the clash between left-wing people who gathered in Taksim Square on February 16, 1969 to protest the 6th fleet of the USA and the right-wing people who were there in response to these protests, which went down in history as ‘Bloody Sunday’. Two people, Ali Turguy Aytaç and Duran Erdoğan, died during the events.