The First Jewish–Roman War began in the year 66 CE, originating in the Greek and Jewish religious tensions, and later escalated due to anti-taxation protests and attacks upon Roman citizens. In response to the Roman plunder of the Second Jewish Temple and the execution of up to 6,000 Jews in Jerusalem, a full-scale rebellion erupted. The Roman military garrison of Judaea was quickly overrun by rebels, while the pro-Roman king Herod Agrippa II together with Roman officials fled Jerusalem. As it became clear the rebellion was getting out of control, Cestius Gallus, the legate of Syria, brought the Syrian army, based on XII Fulminata and reinforced by auxiliary troops, to restore order and quell the revolt. Despite initial advances, the Syrian Legion was ambushed and defeated by Jewish rebels at the Battle of Beth Horon with 6,000 Romans massacred and the "Legio aquila" lost – a result that shocked the Roman leadership.