The Messa da Requiem is a musical setting of the Catholic funeral mass (Requiem) for four soloists, double choir and orchestra by Giuseppe Verdi. It was composed in memory of Alessandro Manzoni, whom Verdi admired, and is therefore also referred to as the Manzoni Requiem. The first performance, at the San Marco church in Milan on 22 May 1874, conducted by the composer, marked the first anniversary of Manzoni's death. It was followed three days later by the same performers at La Scala. Verdi conducted his work at major venues in Europe.
Verdi composed the last part of the text, Libera me, first, as his contribution to the Messa per Rossini which he had begun after Gioachino Rossini had died already contained the music that later begins the Dies irae sequence.