Hezbollah members take part in a military exercise during a media tour in Aaramta, Lebanon on May 21, 2023.

Explosions rocked Beirut on Friday and Saturday as Israeli strikes first targeted Hezbollah leader Hassan Nasrallah, and then on several buildings where the militant group’s rockets are reportedly stored in the Lebanese capital.

While this is a recent escalation in fighting, here’s what you need to know about their fights decades of conflict:

Israeli invasion: Israel took almost half of Lebanon’s territory when its forces invaded in 1982. This included Beirut, where Israeli forces, along with right-wing Israel-allied Christian Lebanese militias, besieged the western part of the capital to drive out Palestinian militants.

The Israeli operation led to the deaths of more than 17,000 people, according to reports and an Israeli investigation into a massacre at a Beirut refugee camp. The investigation held Israel indirectly responsible for the massacre caused by Christian Lebanese fighters.

The rise of Hezbollah: As droves of Palestinian fighters left Lebanon, a band of Shia Islamist militants trained by Iran entered the scene. In 1983, two suicide bombers linked to the faction attacked a U.S. Marine barracks in Beirut, killing nearly 300 U.S. and French personnel and civilians.

A year later, fighters affiliated with Iran bombed the US embassy in Beirut, killing 23 people. In 1985, these militants united around a newly founded organization: Hezbollah.

Support for Gaza: Hezbollah is part of a larger Iranian-led alliance of militant groups in Yemen, Syria, Gaza and Iraq, which has increasingly clashed with Israel and its allies since the start of the war with Hamas – and has vowed to continue will go until the war is over.

Assassination of the main leader: Tensions escalated when Israel said it had killed Hezbollah’s top military commander, Fu’ad Shukr, in an attack on Beirut in July. In retaliation, Hezbollah launched hundreds of drones and missiles at Israel.

Displaced residents: The increase in cross-border fighting has driven people from their homes in both Israel and Lebanon. Israel has set a war goal this month to return tens of thousands of residents of Israel’s north to their homes near the border. More than 100,000 displaced people have been registered in Lebanon, but authorities say the actual number is likely much higher.