 Though originally attributed to the exegete Leo Magistros, Byzantinist Cyril Mango reasons that due to his lack of ever holding of the sakellarios position in addition to being married with children and therefore not being a eunuch, Magistros cannot be the Leo in question.Mango suggests instead that the donor is the same Leo sakellarios that appears as the addressee of a series of surviving Byzantine letters dating from 925 to 944, now kept in the British Museum.Mango asserts that evidence found within the letters suggests that the Bible was made around 940, a claim which has largely been accepted in Byzantinist scholarship.