.. within the Victorian Era of fashion. At this time, with the introduction of trains for passenger transport, the telegraph, and rudimentary telephones, the world – at least Europe – was becoming accessible to many.
This meant Royals such as Eugenie, Empress of France (and later 1st Lady when France became a Republic), with the means, time, and desire to travel, could drop in to stay the week with the Queen of England.
(Photo: Eugenie with her son and husband in about 1861 with yet another gorgeous crinoline. Most likely these are all of silk)