When Lebanon gained its independence with the end of the French mandate in 1946, its population was almost equally divided between Christians and Muslims, with substantial Druze and Armenian minorities. Under French rule an elected legislature had been established, with a convention that the President would be a Maronite Christian, the Prime Minister a Sunni Muslim and the Speaker a Shi’ite Muslim.
During its early years Lebanon enjoyed a measure of prosperity, with Beirut as one of the major banking centres of the Arab world. However, the central government failed to establish an effective unified army, and militias promoting or defending the interests of the leaders of the various religious and ethno-religious groups became a de-stabilising influence.
During the war of 1947-1949, many Arabs fled to Lebanon from northern Israel. Some became well established, with Palestinian students becoming influential at the American University in Beirut. However most lived in refugee camps, denied Lebanese citizenship and equal rights to employment.
After being expelled from Jordan in 1970 following the “Black September” conflict with Jordanian government forces in 1970, the PLO moved the centre of its activities to South Lebanon. In the area adjacent to Israel’s northern border, the PLO effectively established a “State within a State”, and the region became a staging point for infiltration into Israel and rocket attacks on Israeli towns.
The PLO presence precipitated the Lebanese Civil War of 1975, between Christian and Muslim and PLO militias, in which approximately 70,000 Lebanese were killed. During this period some 35,000 Syrian troops entered Lebanon.