 That the custom was as old as the sixth century we know since St. Gregory the Great refers to it, and St. Benedict mentions it in his rule (Pierre Batiffol, "History of the Roman Breviary", 107).This was particularly true of the homilies of Pope Leo I, very terse and peculiarly suited to liturgical purposes.As new feasts were added to the Office, the demand for homilies became greater and by the eighth century, the century of liturgical codification, collections of homilies began to appear (Batiffol, op.