Norma by Bellini is a masterpiece of the Bel Canto period and one of the most famous operas of all time. The opera tells the story of a Druid Priestess who forms an illicit bond with a Proconsul of the Roman army, thereby betraying her people and beginning a chain of events that may lead to war. Bellini's great work contains some of the most beloved music in all opera, including the glorious aria for soprano, "Casta Diva".