On October 7, 2023, Hamas and several other Palestinian militant groups launched coordinated armed incursions from the Gaza Strip into the Gaza envelope of southern Israel, the first invasion of Israeli territory since the 1948 Arab–Israeli War. The attacks, launched on the Jewish holiday Simchat Torah, initiated the ongoing Gaza war.

The attacks began with a barrage of at least 4,300 rockets launched into Israel and vehicle-transported and powered paraglider incursions into Israel. Hamas militants breached the Gaza–Israel barrier, attacking military bases and massacring civilians in 21 communities, including Be'eri, Kfar Aza, Nir Oz, Netiv Haasara, and Alumim. According to an Israel Defense Forces (IDF) report that revised the estimate on the number of attackers, 6,000 Gazans breached the border in 119 locations into Israel, including 3,800 from the elite "Nukhba forces" and 2,200 civilians and other militants. Additionally, the IDF report estimated 1,000 Gazans fired rockets from the Gaza Strip, bringing the total number of participants on Hamas's side to 7,000.

In total, 1,195 people were killed: 736 Israeli civilians (including 36 children), 79 foreign nationals, and 379 members of the security forces. 364 civilians were killed and many more wounded while attending the Nova music festival. At least 14 Israeli civilians were killed by the IDF's use of the Hannibal Directive. About 250 Israeli civilians and soldiers were taken as hostages to the Gaza Strip.