What is the fine-grained topic of the following text: The lead vessel, L'Aigle, bore Empress Eugenie of France and De Lesseps, followed in succession at 10-minute intervals by the festooned craft of the emperor of Austria, the crown prince of Prussia, and the prince and princess of Holland, and over 40 other assorted yachts and warships. Only return the topic.
Empress Eugenie of France's voyage with De Lesseps and other royals.