Warning: contains spoilers for the All Souls books.
Vampire families are complicated, and not just because everybody has two birthdays to remember. Each vampire has a sire who becomes their vampire blood-mother or father, and any vampires who share a sire automatically become siblings. If a vampire’s sire is mated to another, that vampire becomes a non-blood parent to their shared ‘children’.
The immortality thing also means that multiple generations of a vampire clan often look around the same age, which is why, if the de Clermonts in A Discovery of Witches ever had a family get-together, it’d look more like an office costume party.
To set it straight, here’s how the TV show’s complex de Clermonts are all related:
Matthew was sired by Ysabeau de Clermont in the 6th century, making her his blood-mother. Her mate Philippe de Clermont is Matthew’s non-blood vampire father. Baldwin and Louisa – vampires sired respectively by Philippe and Ysabeau – are Matthew’s surviving brother and sister (surviving in the 17th century at least).
In Deborah Harkness’ All Souls books, other siblings are mentioned, including Louisa’s twin brother Louis, also sired by Ysabeau but dead by the time of A Discovery of Witches; and the vampires sired by Philippe: Hugh (who sired Gallowglass, making him Matthew’s nephew), Godfrey, Stasia, Freyja and Verin.
Philippe’s only surviving blood-son in the present day, Baldwin was sired by the de Clermont patriarch during the time of the Roman Empire, making him Matthew and Louisa’s older brother, and the nominal head of the family after Philippe’s death at the hands of the Nazis in the 1940s. Baldwin occupies the de Clermont seat on ruling organisation the Congregation, but covets leadership of the Knights of Lazarus, both established by Philippe de Clermont.
In Harkness’ books, Baldwin has one vampire daughter, named Miyako.
Philippe de Clermont
The family patriarch, Philippe de Clermont was sired in Ancient Greece (his alias Alcides Leontothymos is an allusion to the divine hero Heracles) and in turn sired three sons and three daughters: Hugh, Godfrey, Baldwin, Stasia, Freyja and Verin. Through his mate Ysabeau, he is the father to Matthew, Louisa and Louis.
Ysabeau de Clermont
Ysabeau is the blood sire of Matthew, Louisa and Louis in the All Souls books, the mate to Philippe de Clermont, and through him, the mother of Hugh, Godfrey, Baldwin, Stasia, Freyja and Verin. The traumatic circumstances of Ysabeau’s own siring left her a carrier of a genetic disease known as ‘Blood Rage’, which she passed on through her bloodline.
A US medic who crossed paths with Matthew Clairmont during the 18th century American Revolutionary War, Marcus was sired on his deathbed by Matthew, who promised to help advance his medical career. Marcus’ aunts and uncles are Matthew’s brothers and sisters, and his grandparents Ysabeau and Philippe de Clermont. Gallowglass is Marcus’ cousin.
Marcus is a carrier of Blood Rage, through Ysabeau’s line, which is why Matthew culled the ‘children’ he sired in New Orleans at the turn of the 19th century.
Louisa de Clermont
Sired by Ysabeau de Clermont, Louisa is the daughter of Ysabeau and Philippe and sister to Matthew. Like him, she suffers from Blood Rage inherited through Ysabeau’s line.
The vampire son of Hugh, eldest blood-son of Philippe de Clermont. Hugh was executed in France, so his son harbours resentment towards the French King and Church.
All episodes of A Discovery of Witches season 3 are available to stream on NOW TV.