As reported by the historian Flavius Josephues (c.37-100), some 960 Jewish zealots committed suicide by cutting each others’ throats at Masada, Israel, in AD 73, as the palace was being beseiged by Romans.
The men killed all the women and children, then drew lots to select ten men. The ten slew all the other men, then the ten drew lots to chose one man, who in turn killed the other nine. The remaining one man then fell on his own sword.
In modern times, the greatest mass suicide was on 18 Nov 1978 when 913 members of the People’s Temple cult died of a mass cyanide poisoning at Jonestown, newr Port Kaituma, Guyana.
Some 7,000 Japanese committed suicide, many of them jumping off cliffs to their deaths, in July 1944 during the US assault of the island Saipan.