Though set in a specific time and place, Tosca is not a historical drama. It is, however, largely consistent with the historical events of the time in which it was set. For about two years prior to the events of the opera, Rome had been ruled by the Parthenopean Republic, under the influence of the French during which time the Pope had been driven into exile (the establishment of an independent Italian nation was still decades in the future). While beloved of the intelligentsia, the Republic lacked popular support and was soon overthrown, leading to an oppressive regime which sought to stifle all opposition and had several sympathizers of the Republic executed.
The battle of Marengo happened pretty much as depicted in the opera. Napoleon’s troops were surrounded, leading to a premature report of his defeat, but he was saved by the arrival of some last-minute reinforcements, and the anti-Napoleon factions in Rome soon learned the bitter truth. At the time, many of the intelligentsia in Europe were supporters of Napoleon (though several became disillusioned later) and, like Cavaradossi, would have cheered the actual result. In the play, Cavaradossi was partly of French ancestry, a fact which also would have contributed to his political leanings.
Historian Deborah Burton has identified counterparts for some of the characters in the play. There was a counsel of the Republic with a similar name to Angelotti’s, Liboriio Angelucci. Fortunately for him, he successfully escaped Rome after the fall of the Republic. Some years later a man named Francesco Angelotti was imprisoned for anti-government activities and was killed during an escape attempt.
Like Angelotti, the character of Scarpia also appears to be a composite of two historical figures. There was a real-life baron who went by the pseudonym “Sciarpa” (the scarf). Like his counterpart in the play, he masked his cruelty with a show of outward piety. In some ways, however, Scarpia bears a closer resemblance to Vincenzo Speciale. Like the Scarpia of the play, he was from Sicily and presided over courts which condemned numerous suspected enemies of the state to death, though he worked in Naples rather than Rome. Among the victims was Eusebe Palmieri, whose execution is also referred to in the opera.
Historian Susan Vandiver Nicassio has argued that the events of the play, in fact, better describe the situation in Naples than that of Rome, but the Roman setting appealed more to Sardou (and later to Puccini) because Rome represented the oppressive power of the Church, appealing to Sardou’s political liberalism and Puccini’s anti-clericism.