Offenbach's career was at its height in the 1860s with the premieres of some of his most popular and enduring works, such as "La Belle Hélène" (1864) and "La Vie parisienne" (1866). With the original production of the latter still running, Offenbach and his librettists hurried to prepare a new opera, "La Grande-Duchesse de Gérolstein", to play during the Paris Exposition ("Exposition universelle") of 1867. Offenbach assisted Meilhac and Halévy in shaping the libretto. They were eager to ensure a hit, and so they engaged the immensely popular Hortense Schneider, who had created the title role in "La Belle Hélène", among other Offenbach roles, paying her the extraordinarily rich monthly sum of 4,500 francs. Schneider, in addition to her vocal gifts, was well able to portray the commanding and saucy character of the Grand Duchess, which parodied Catherine the Great.