Founded in 1964, the PLO has long been the umbrella group for numerous Palestinian political, professional and trade groups, all dedicated to the establishment of an independent Palestinian state. In 1969, Yasser Arafat, representing the Fatah movement, became chair of the organization, a position he held until his death in 2004. Some of the other groups within the PLO are the Popular Front for the Liberation of Palestine (PFLP), the Democratic Front for the Liberation of Palestine (DFLP), and the Syrian-backed Saeqa. From the early 1970s through the early 1990s, the PLO operated politically and militarily from bases in Jordan, Lebanon, Syria and Tunisia. The PLO first gained international legitimacy when Arafat addressed the United Nations General Assembly in November 1974 and the organization was granted observer status to the United Nations. In 1993, the PLO received recognition from Israel as the representative of the Palestinian people and recognized Israel’s right to exist through signing on to the Oslo Process; it has since seen its leadership absorbed into the Palestinian Authority. Some factions of the PLO still do not recognize Israel’s right to exist. Per a unity agreement between Palestinian political parties in 2011, Hamas may join the PLO. See Bickerton, Ian J and Carla L. Klausner. A History of the Arab-Israeli Conflict, 5th ed. New Jersey: Pearson Prentice Hall, 2007; Hamid, Rashid. “What is the PLO?” Journal of Palestine Studies Vol. 4, No. 4. (Summer 1975), pp. 90-109; and “Palestine Liberation Organization.” Permanent Observer Mission of Palestine to the United Nations. 22 August 2011. http://www.un.int/palestine/theplo.shtml.  http://www.justvision.org/glossary/palestine-liberation-organization-plo