The day began with shootings near the church in Ain al-Rummaneh, where Pierre Gemayel was attending a consecration; his bodyguard Joseph Bou Assi was killed. In the early afternoon Kataeb militiamen fired on a bus returning to Tal al-Za'tar from a rally of the Arab Liberation Front. Most historians count 27 dead (Hanf, Fisk, de Clerck and Malsagne: 27 of 35 passengers); Traboulsi gives 21 and Ménargues 31. According to de Clerck and Malsagne the bus carried Palestinians and Lebanese in equal numbers, all men. Fighting spread that evening across the suburbs of Beirut.

De Clerck and Malsagne and Tegho Bou Nassif date Zahleh's entry into the war to 24 August 1975, when Palestinian fighters planted a bomb in its tourist district, Wadi al-Arayish. In Hanf's account, Zahleh's Christians and Shi'is of its outskirts and nearby villages, helped by Palestinian guerrillas, came to blows late in August after a non-political arcade quarrel. Three Zahleh men were executed at the end of August.

Ménargues has William Hawi shot by a Palestinian sniper in June 1976, at the end of the Tal al-Za'tar siege; Traboulsi places it during the siege. Bashir Gemayel succeeded him as Kataeb militia chief.

Hanf has the Syrian army moving again only once Tal al-Za'tar had fallen, increasing pressure on the encircled Palestinian and leftist forces in the Upper Metn; these were expelled at the end of September.

Ratified by an Arab summit in Cairo on 25 October, the Riyadh decisions required all parties to surrender heavy weapons and the Palestinians to return to the zones granted by the 1969 Cairo Agreement, and created a 30,000-man Arab Deterrent Force under President Sarkis, its largest contingent by far, 25,000-27,000 men, being the Syrian troops already in Lebanon. Saudi Arabia had sent the invitations on 15 October; the leaders of Saudi Arabia, Kuwait, Egypt, Syria and Lebanon met the PLO chairman in Riyadh on 16, 17 or 18 October, depending on the historian. The cease-fire's start is dated 16 October (Hanf), 21 October (Traboulsi) or 15 November (de Clerck and Malsagne).

Historians date the Ehden killings to 13 June (de Clerck and Malsagne) or 14 June (Hanf). A unit of some 200 men (Traboulsi) led by Samir Geagea attacked the Frangieh residence; besides Tony Frangieh, his wife and their three-year-old daughter, about thirty relatives and supporters were killed. The Phalange presented the raid as retaliation for the killing of their local leader Jud al-Bayeh in early June; Bashir Gemayel denied ordering the killing of the family. The raid also turned on control of the Chekka cement works. Syrian troops then occupied Ehden and much of the north.

Hanf writes that the Lebanese Front was left with an enclave of roughly a tenth of Lebanon once Syrian troops had moved into the northern Christian mountains, Koura, Batroun and the coast as far as the Madfoun bridge. Frangieh gave Kataeb members in the north until the month's end to give up their weapons and quit the party, or else leave.

Hanf: early in 1980 Amal fought the Iraqi-backed Arab Liberation Front in Beirut's suburbs while Fatah tried to mediate, as relations between Shi'is and Palestinians grew worse; the fighting later reached the south.