But even the bulls of such a pontiff as Innocent III are not unfrequently at fault, and as Léopold Delisle has shown, an erroneous calculation of the indiction may be perpetuated through a whole series of authentic documents (Bib. The point of main interest in this connection is to determine the source and period of the introduction of our present system of dating by the Christian Era.Although, as explained in the article GENERAL CHRONOLOGY, the monk known as Dionysius Exiguus, when resident in Rome, c.
, the first word of the formula, came to be used for the time and place therein specified.
The principle that imperial decrees and charters must be "dated" as a condition of validity, i.e.
that they must bear upon them the indication of the day and year when they were delivered, may be traced back to the time of Constantine.
In the course of the Middle Ages this principle was generally admitted, and we find, for example, that at Cologne in the twelfth century the validity of a certain instrument was contested because it lacked a date. now the Roman decrees lay down that letters which lack the day and the indiction have no binding force." (Westdeutsche Zeitschrift für Geschichte, I, 377.) But although this principle was recognized in theory it was not always carried out in practice.
"Those who have seen it say that the document which John brought does not bear the day or the indiction . Even down to the beginning of the twelfth century not only royal and imperial letters but even charters (), properly so called, were occasionally through the carelessness of officials sent out without a date.
(Bresslau, Handbuch, I, 891.) In this matter the Italian chancery officials seem to have been much more careful than those of the rest of Europe.The same is true with regard to the correctness of the dates which do appear in official documents, especially those of the early Middle Ages.As a rule the charters emanating from the chancery of the Western Emperors are much more liable to this form of error than those of the Holy See (Bresslau, ib., 844). In any case it remains certain and is admitted by all serious writers upon diplomatics that the mere fact that an erroneous date occurs in a document, especially when we are dealing with the earlier Middle Ages, cannot by itself be accepted as a proof, or even a presumption, of the spuriousness of the document.Gregory the Great the Dionysian Era is not adopted.It was the pope's habit to date his letters by the regnal years of the emperor and letters so dated may be seen in Bede's "Ecclesiastical History", just as they were copied from the Roman archives.Apparently it was the Englishman Bede himself who was the first to bring the Dionysian system into general use, for it was through him that it was adopted in literature, having been employed systematically not only in his "De Temporum Ratione" but especially in his "Ecclesiastical History".