Why was La traviata considered a risky opera subject in the 1850s?

In the mid-19th century, La traviata was considered a risky subject primarily because it departed from the traditional operatic focus on heroic or noble themes, opting instead for an intimate, bourgeois setting.1

The opera’s subject matter was viewed as risqué because its protagonist, Violetta Valéry, is a "fallen woman"—a courtesan who earns redemption through sacrifice. While this narrative was not strictly forbidden by censors, it challenged the social and moral conventions of the time.12

Furthermore, Giuseppe Verdi insisted that the opera be set in the contemporary 1850s with modern costumes, a decision that met with resistance from opera companies. They preferred to distance the potentially scandalous story from the present day by setting it in the early 18th century. This insistence on realism, combined with the unconventional portrayal of a courtesan as a sympathetic heroine, made the work a bold and controversial departure from the established operatic norms of the era.1