The Lebanese Civil War (Arabic: الحرب الأهلية اللبنانية Al-Ḥarb al-Ahliyyah al-Libnāniyyah) was a multifaceted armed conflict that took place from 1975 to 1990. It resulted in an estimated 150,000 fatalities and led to the exodus of almost one million people from Lebanon.
The religious diversity of the Lebanese people played a notable role in the lead-up to and during the conflict: Lebanese Christians and Lebanese Sunni Muslims comprised the majority in the coastal cities; Lebanese Shia Muslims were primarily based throughout southern Lebanon and in the Beqaa Valley in the east; and Druze and Christians populated the country's mountainous areas. At the time, the Lebanese government was under the influence of elites within the Maronite Christian community. The link between politics and religion was reinforced under the French Mandate from 1920 to 1943, and the country's parliamentary structure favoured a leading position for Lebanese Christians, who constituted the majority of the population. However, Lebanon's Muslims comprised a large minority and the influx of thousands of Palestinians—first in 1948 and again in 1967—contributed to Lebanon's demographic shift towards an eventual Muslim majority. Lebanon's Christian-dominated government had been facing increasing opposition from Muslims, pan-Arabists, and left-wing groups. The Cold War also exerted a disintegrative effect on the country, closely linked to the political polarization that preceded the 1958 Lebanese crisis. Christians mostly sided with the Western world while Muslims, pan-Arabists, and leftists mostly sided with Soviet-aligned Arab countries.