From SuspireWiki

Marquis is the Title of Tribute bestowed upon a vampire who is given permanent place on the Inner Circle of a city. This is an extremely high honor, suggesting that no fault or mishap could ever diminish the influence this vampire has within the Invictus. This title is normally given to one who has clearly altered the course of history within the city to the covenant’s advantage, and without whom (it is acknowledged), all would have been lost. The name of the city in question is appended to the title (for example, The Marquis of Florence). No more than one vampire may hold this title in a city at a time. Traditionally, only Final Death or permanent exile can free the title to be conferred upon another. The Right Honorable precedes the name of a Marquis or Marquise in introduction.