The Karantina massacre took place on January 18, 1976, early in the Lebanese Civil War. Karantina was a predominantly Palestinian Muslim district in mostly Christian East Beirut, controlled by forces of the Palestine Liberation Organization (PLO), and inhabited by Kurds, Syrians, Armenians, and Palestinians. The fighting and subsequent killings also involved an old quarantine area near the port and nearby Maslakh quarter.Karantina was overrun by militias of the right-wing and mostly Christian Lebanese Front, specifically the Kataeb Party (Phalangists), resulting in the deaths of approximately 1,500 people, mostly Muslims. After Kataeb Regulatory Forces (KRF), Guardians of the Cedars (GoC), NLP Tiger militia and Lebanese Youth Movement (LYM) forces took control of the Karantina district on 18 January 1976, Tel al-Zaatar was placed under siege, leading to the Tel al-Zaatar massacre.The Damour massacre was a reprisal for the Karantina massacre.

Christianity in Lebanon has a long and continuous history. Biblical Scriptures purport that Peter and Paul evangelized the Phoenicians, whom they affiliated to the ancient patriarchate of Antioch. The spread of Christianity in Lebanon was very slow where paganism persisted especially in the mountaintop strongholds of Mount Lebanon. A 2015 study estimates some 2,500 Lebanese Christians have Muslim ancestry, whereas the majority of Lebanese Christians are direct descendants of the original early Christians.The Maronite Catholics and the Druze founded modern Lebanon in the early eighteenth century, through a governing and social system known as the "Maronite-Druze dualism" in the Mount Lebanon Mutasarrifate. Proportionally, Lebanon has the highest rate of Christians in the Middle East, where the percentage ranges between 34% and 40%, followed directly by Egypt and Syria at roughly 10%, and Jordan at 3 to 6%. Lebanon's displaced population and diaspora, estimated at 12 million to 20 million people, are Christian - estimated at 85% of the total diaspora.