Original: This dispute originated in a disagreement over the production of his Giovanna d'Arco in 1845; however the composer later conducted his Requiem there on 25 May 1874, and in 1886 announced that La Scala would host the premiere of his opera Otello.
Simplified: However the composer later conducted his Requiem there on May 25, 1874, and in 1886 announced that La Scala would host the premiere of his opera Otello.