The nephew of Duke de Polignac, Henri was made a darkling some time after 1787, presumably during a blood party thrown by Saint Cloud. After he became the vampire's subjugate, he went back home to take his sister Brigitte with him.
Like a typical subjugate, Henri was fiercely loyal and devoted to his master, Saint Cloud. Because he was often doing Saint Cloud's bidding, the warlock Magnus Bane was well-acquainted with Henri and dreaded what Magnus called his boring presence.
In June 1791, Henri encountered Magnus and invited him to Saint Cloud's party. At the evening of the party, Henri greeted Magnus and introduced him to Brigitte, with whom Magnus' observation implied that Henri was having an incestuous relationship.
During the party, a vampire named Coselle found Queen Marie Antoinette. The other vampires and Henri and were enthusiastic to report it to Saint Cloud. Saint Cloud later instructed him and Charles to accompany Magnus and the Queen to the blue room.
When Saint Cloud had his revenge on Magnus for stealing the queen, Henri was left to wait for him and give him a message. Magnus, refusing to come with him, threatened him with magic and asked him to leave.
- The Runaway Queen (first and only appearance)