Un ballo in maschera
The opera was first performed at the Teatro Appollo in Rome, on February 17, 1859. One of Verdi's richest  middle-period works, it relates the events surrounding the assassination of King Gustav III of Sweden, but because of censorship, the story was transposed to 17th century Boston, with Gustav becoming an English governor, Richard of Warwick. Nowadays, most productions present the opera in its original Swedish setting.