"Black September" refers to a conflict that occurred in Jordan in September 1970, primarily between the Jordanian government and the Palestinian Liberation Organization (PLO). Tensions escalated as the PLO, which had established a strong presence in Jordan, began to challenge the authority of King Hussein. The conflict resulted in violent clashes and significant loss of life. The Jordanian military launched a campaign to regain control, leading to the expulsion of many Palestinians from the country. This event marked a turning point in the relationship between Jordan and the Palestinian people, influencing regional politics and the future of the Palestinian cause.