The foster-sister of Robert le Diable, and bride of Rambaldo, the Norman troubadour. She came to Palermo to place in the duke's hand her mother's will, which he was enjoined not to read till he was a virtuous man. When Bertram, his fiend-father, tempted his son to evil, Alice proved his good genius; and when, at last, Bertram claimed his soul as the price of his ill deeds, Alice read the “will,” and won him from the evil one. —Meyerbeer's Opera, Roberto il Diavolo.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Alice from Infoplease: