An Imperial Wedding was what happened when an Emperor of Barrayar got married. "The most recent wedding of a ruling emperor had been the scrambling mid-war union of Gregor's grandfather Emperor Ezar to the sister of the soon-to-be-late Mad Emperor Yuri, which for a number of sound historical and aesthetic reasons Alys was loath to take as a model. Most other emperors had been safely married for years before they landed on the throne. Prior to Ezar one had to go back almost two hundred years, to the marriage of Vlad Vorbarra le Savante and Lady Vorlightly, in the most gaudily archaic period of the Time of Isolation." ―Imperial Weddings