Complex sentence: Rupert's stepmother, staged two repertory seasons at the Savoy Theatre, directed by Gilbert, with much success, revitalising the D'Oyly Carte Opera Company, which had been in decline after his father's death.
Split into simpler sentences: Rupert's stepmother, staged two repertory seasons at the Savoy Theatre. Directed by Gilbert and received with much success, they revitalised the D'Oyly Carte Opera Company, which had been in decline after Richard D'Oyly Carte's death.