The Palestinian camps of Tall El Zaatar and Jisr El Bacha being under a blockade, 1200 armed elements attacked the region of Horsh Tabet.
Pitched battles opposed Phalangist and Fedayin activists.

After a day marked by the resignation of Rachid Karameh and the aggravation of the war of barracks in Tripoli, a military Coup was executed by Corporal Aziz Ahdab, commanding the place of Beirut. Corporal Ahdab was supported by the Commander of the army, 270 loyalist officers, Syria, and the Palestine Liberation Army. He claimed the resignation of Sleiman Frangieh, but the President refused to give up and locked himself in Baabda.

The 'Holiday Inn' occupied by the Phalange Party fell in the hands of the Mourabitun and their allies.
According to some sources, the Phalange Party succeeded in evacuating some of its militiamen who took with them seven dead bodies, three of which were young girls. According to other sources, 65 militiamen were able to run away using an underground passage. The Holiday Inn had been subject to repeated assaults for the past ten months.

Elias Sarkis, the 52 years old Central Bank Governor, was elected President of the Republic at the second ballot by a majority of 66 votes out of 69 attending deputies.
The election took place in a tense atmosphere at the villa Esseily-Hussein Mansour, which was turned into a temporary Parliament around which mortar shells were falling. Lebanese leftist parties were opposed to the elections.

An avalanche of missiles and shells hit Beirut while combats continued on all fronts. The bombings reached the airport, imposing the closure of runways to air traffic at night.

Violent combats opposed pro-Syrian formations to Palestinian Progressive militiamen in several districts of Beirut. Syrian troops entered the capital where most Palestinian Progressive forces were concentrated.

The Lebanese Front approved the application of the solutions of the sub-summit, concerning the dispatch, to Lebanon, of a peace force including Libyan, Algerian, Syrian, Sudanese, Saudi, and Palestinian contingents.

The US ambassador in Lebanon, Francis Meloy, the US economic advisor, Robert Waring, and the driver of the US embassy were assassinated after being kidnapped. They were about to cross the borderline between West and East Beirut.

After a siege that lasted 52 days, the Tall El Zaatar Palestinian camp fell in the hands of the Lebanese Forces as a result of an ultimate assault launched at dawn. It was in total confusion that the 12000 camp residents were evacuated. In retaliation, kidnappings were reported in West Beirut.

The Syrian forces and the Lebanese Forces launched an attack against the positions of the Palestinian Progressive forces in the mountain. This far-reaching attack aimed at dislodging the Common Forces from the crests they occupied in Sannine, Zaarour, Aintoura and Mtein. This assault was accompanied by an intensive bombing of Aley, the main Palestinian Progressive base in the mountain.

A restricted summit was held in Ryad.
While shells kept falling by hundreds on residential neighborhoods in Beirut, killing and injuring tens of persons, an Arab summit was held in Ryad attended by Presidents Elias Sarkis, Anwar Sadate, Hafez El Assad, the Emir of Kuwait, King Khaled of Saudi Arabia, and Yasser Arafat chairman of the PLO.
This meeting aimed at reaching an agreement ending the Lebanese crisis. It contained the following clauses:
• Starting October 21, putting a final end to fights on all the Lebanese territory.
• Reinforcing the Arab Peace Force in Lebanon
• Entrusting the Arab Strike Force counting 30,000 men, with the duty of ending the combats and repressing any party that violates the cease-fire. It was also in charge of executing the Cairo agreement, as well as maintaining security in the country, collecting heavy armaments and helping the Lebanese authorities to regain control of all public services and institutions.

Phase 2 of the peace plan started.
The Arab Strike Force including mainly Syrians started to advance on various axes leading to the heart of the capital, as well as the Chouf, the Kesrouan, and Jbeil. 8,000 infantrymen and 250 armored vehicles converged towards the districts of Beirut and the front line.

According to Ghassan Tueni, who was in Geneva asking for help from international organizations, "In 18 months, the Lebanese war killed 60,000 persons, injured 200 000 others, and made 1.7 million homeless persons."