How did Hezbollah emerge during the Lebanese Civil War?

Hezbollah emerged during the Lebanese Civil War as a Shiʿi militia following the 1982 Israeli invasion of the country.1

The organization was formed by a group of Lebanese Shiʿi clerics who were influenced by the 1979 Islamic Revolution in Iran. Seeking to drive Israel from Lebanon and establish an Islamic republic, the group drew its initial manpower largely from younger, more radical members of the moderate Amal movement.2

Based in the Bekaa valley, southern Lebanon, and southern Beirut, the group coordinated closely with Iran to secure logistical support. Throughout the 1980s, it engaged in attacks against Israel and participated in the civil war, often clashing with Amal. Unlike most other militias, Hezbollah was not disarmed when the civil war concluded in 1990, allowing it to continue a guerrilla campaign against the Israeli occupation of southern Lebanon.2