Based on Victorien Sardou’s 1887 French-language play, Giacomo Puccini’s Tosca of 1900, with a libretto by Luigi Illica and Giuseppe Giacosa, occurs on a precise date that can be linked to an historical event. All of the action takes place during the afternoon, evening and early morning of 17 and 18 June 1800, following the Battle of Marengo between Napoleon’s army and Austrian forces. The Austrians were initially triumphant and sent news of victory back to...