Complex sentence: In 1815 she was cast as the heroine in Flore et Zéphire, one of the first romantic ballets of the time, choreographed by Charles Didelot who was the chief choreographer of the Russian Imperial Ballet.
Split into simpler sentences: In 1815 she was cast as the heroine in Flore et Zéphire, one of the first romantic ballets of the time. The ballet was choreographed by Charles Didelot, the chief choreographer of the Russian Imperial Ballet.