Abstract: The present research is concerned with 1969-Cairo Agreement between Lebanon and  PLO, which was a turning point in the history of the Lebanese-Palestinian relations and to the military Palestinian presence on the Lebanese territories. The Agreement came as a result of a series of clashes and cases of tension between the Palestinian organizations and the Lebanese Authority which tried to eliminate the guerrilla operations carried out by these organizations during a period which represented the peak of the guerrilla action.

The research also reflects on  the circumstances and crises experienced by the military Palestinian presence in Lebanon, especially in 1969, and the reactions to the Agreement.