The Theatres Act 1843 broke the patent theatres' monopoly of drama. At that time Her Majesty's Theatre in the Haymarket was the main centre of ballet and opera but after a dispute with the management in 1846 Michael Costa, conductor at Her Majesty's, transferred his allegiance to Covent Garden, bringing most of the company with him. The auditorium was completely remodeled after an 1846 fire, during the following 1846–47 seasons, the company performed at the Lyceum Theatre. The theatre reopened as the Royal Italian Opera on 6 April 1847 with a performance of Rossini's "Semiramide".