The principles on which Jerome went in his revision of the text have been already referred to, but what the early Greek manuscripts were that he employed is not yet clearly made out. The relics of the material he used are as scanty as those of his own work. He must, however, have been able to make use of manuscripts that went back to Eusebius, seeing that he adopted the Eusebian Canons in his New Testament. But there are certain readings in Jerome which we have not yet been able to discover in any Greek manuscript that we know. For instance, he gives _docebit vos omnem veritatem_ in John xvi. 13, where our present Greek editions read ὁδηγήσει ὑμᾶς ἐν τῇ ἀληθείᾳ πάσῃ, so that he would seem to have read διηγήσεται ὑμῖν τὴν ἀλήθειαν πᾶσαν. As a matter of fact, this reading does occur in two passages of Eusebius and in Cyril of Jerusalem, as well as in the Arabic version of Tatian, but it has not been discovered in any Greek manuscript.[104] In the other parts of the New Testament, the revision of which was perhaps completed by the year 386, Jerome inserted hardly any new readings from the Greek, but contented himself with improving the grammar and diction of the Latin. His work on the Old Testament was much more comprehensive, but does not fall to be discussed here. [Sidenote: History of the Vulgate.] It was only by degrees that Jerome’s recension gained ground. In Rome, Gregory the Great (d. 604) for one preferred it to the old, though at the same time he says expressly: sedes apostolica, cui auctore Deo praesideo, utraque utitur. [Sidenote: Alcuin.] Owing to the use of both forms the diversity of copies grew to such an extent that in 797 Charles the Great ordered =Alcuin= to make a uniformly revised text from the best Latin manuscripts for use in the Churches of his Empire. For this purpose Alcuin sent to his native Northumbria for manuscripts, by which he corrected the text of the Bible, and he was able to present the first copy to the Emperor at Christmas 801. A good many of the superb _Carolingian_ manuscripts, as they are called, which are found in our libraries, contain Alcuin’s Revision, as for instance the Bible of Grandval near Basel, which was probably written for Charles the Bald, and which is now in the British Museum (see Plate VII.); the Bible presented to the same monarch by Vivian, Abbot of St. Martin of Tours, which was sent by the Chapter of Metz from the Cathedral treasury there to Colbert in 1675, and is now in Paris (B. N., Lat. 1); another written in the same monastery of St. Martin, and now at Bamberg; and that in the Vallicellian Library of the Church of Sta. Maria in Rome, which is perhaps the best specimen of the Alcuinian Bible. [Sidenote: Theodulf.]