 Gregory of Tours, writing in the 6th century, said that Gereon and his companions were a detachment of fifty men of the Theban Legion who were massacred at Agaunum by order of Emperor Maximian for refusing to sacrifice to pagan gods to obtain victory in battle.Some of his companions' names are stated as being Cassius, Gregorius Maurus, Florentius, Innocentius (Innocent), Constantinus, and Victor.Saint Bede mentions that their feast was included in the Sarum calendar, as well as the calendars of Barking and Durham.