Crispus's year and place of birth are uncertain. He is considered likely to have been born between 299 and 305, possibly as early as 295, somewhere in the eastern Roman Empire. The earliest date is most likely, since he was being tutored in 309–310 by Lactantius. His mother Minervina was either a concubine or a first wife to Constantine. Nothing else is known about Minervina. His father served as a hostage in the court of Diocletian in Nicomedia, thus securing the loyalty of Constantine's father, Constantius Chlorus, who was "caesar" to Maximian in the west at this time.