Materna Julius of the Julii clan is the sire of Lucius. She is the ancestor and protector of Lucius’s family. Not much is known about her other than she’s politically active and she is not seen for long periods of time. She has her own place somewhere and does not sleep in the collamberium with the others in the coterie.
Materna is probably one of the few vampires in Rome that Julius respects.