Six years passed between the première of La Traviata, chronologically the last great Verdi opera we have discussed, and that of Un ballo in maschera, which was given on 17 February 1859 at the Teatro Apollo, Rome, the theatre which had earlier given the first performances of Il Trovatore. The two Roman operas are bound together by strange links, which I shall later attempt to unravel. But at this point we might usefully try to develop (not explain, as nothing can be explained in artistic creation) the ideas which held Verdi's attention during this long interval – a period which saw the composition of two minor operas: Aroldo, a revision of the Stiffelio which had failed at Trieste, and I vespri siciliani, which followed the unfortunate Jérusalem in attempting (dubiously as far as artistic convictions were concerned) to win over the despised bastion of the Paris Opéra.

The critics usually submit that Verdi composed I vespri siciliani against his will, that he was prevented from full involvement by a clumsy, stolid, confused libretto provided by the ‘Scribe workshop’ – it was in fact a typical commercial item, and was also signed by a collaborator, Duveyrier – and by the necessity of writing music to be sung in French, in what remained a hostile atmosphere.