Gaul has been conquered by the Romans. Oroveso, the Arch-Druid longs to lead a Gallic rebellion against the colonial forces. He and all the others wait for the signal to be given by his daughter, the Druid High Priestess Norma. But Norma has fallen in love with the Roman Proconsul, Pollione, and given birth to two children. They have been brought up in secrecy by her confidante Clotilde. Norma still loves Pollione but he has fallen in love with a novice priestess, Adalgisa.