Italian settings were immensely popular. This can be seen in 'The White Devil' where Vittoria is described as being a 'Venetian Curtizan' despite not being from Venice or a courtesan.
The tagline allowed Webster to indicate that this play is concerned with political and sexual intrigue. Italy and in particular Venice were associated with both. Roger Ascham wrote about this in The Schoolmaster:
"In one city, more liberty to sin than I ever heard tell of in our noble city of London in nine years."
The stereotype was ingrained as Thomas Coryat wrote: "the name of a Cortezan of Venice is famoused over all Christendom."
Although Italy was seen as a hotbed of vice and passion. Venice was especially renowned for its courtesans or high-class prostitutes. They were well-educated, cultivated, beautiful and well-dressed, sometimes aristocratic by birth, sometimes kept by wealthy nobles and often shrewd business women who profited handsomely by their trade..
Sex was only one aspect of it. In aristocratic culture marriage was a dynamic arrangement and couples often led seperate lives. The courtesan could provide the companionship and friendship not expected of a wife. Making Vittoria Venetian is a shortcut in her characterisation and explaining the nature of her relationship with Bracciano.
As Jones argues: "If Vittoria comes across as less... she distills English fantasies of Italianate excesses into an unstable personification of Venetian vice and allure."
Italy was not just associated with sex but also with the murky world of politics. The Catholic Church were depicted as particularly corrupt. England had been Protestant since the reign of Elizabeth I and Catholics were viewed with extreme suspicion. Lurid tales of sexual scandal, political corruption. passion, jealously and even revenge set in Italy were a favorite literary theme. As Isabella states: "My jealousy/ I am to learn what that Italian means."
"The Italy of English playwrights from the 1580s on was not a geographer's record but a fantasy setting for dramas of passion, Machiavellian politics and revenge- a landscape of the mind." - Ann Rosalind Jones
Webster was not the only playwright to set his plays in Italy. Shakespeare's "The Merchant of Venice", "The Taming of the Shrew", Ben Johnson's "Volpone" and John Ford's "Tis Pity She's a Whore' were all set in Italy. Italy was associated with the refined aristocratic manners on one hand and on the other the analysis of ruthless realpolitik of Renaissance princes.