<P> Tosca ( Italian pronunciation : ( ˈtoska ; ˈtɔska ) ) is an opera in three acts by Giacomo Puccini to an Italian libretto by Luigi Illica and Giuseppe Giacosa . It premiered at the Teatro Costanzi in Rome on 14 January 1900 . The work , based on Victorien Sardou 's 1887 French - language dramatic play , La Tosca , is a melodramatic piece set in Rome in June 1800 , with the Kingdom of Naples 's control of Rome threatened by Napoleon 's invasion of Italy . It contains depictions of torture , murder and suicide , as well as some of Puccini 's best - known lyrical arias . </P>
three act puccini opera first performed in 1900
Tosca