It is not, however, possible to speak, as many liturgists do, of a Marian ecclesiastical year. For the dates of our Lady’s feasts, viewed in their chronological order, overlap the limits of the year, and being subject to the same principles which regulate saints’ days, fall invariably on fixed days in the Calendar, and so cannot be said to form an integral part of the ecclesiastical year. Nevertheless they form in themselves a cycle of festivals, as is also the case in a lesser degree with regard to St John the Baptist. Two of them, however, have been brought into connection, at least externally, with the ecclesiastical year, _i.e._ the Annunciation, whose date depends upon Christmas, and the Visitation, whose date is regulated by the births of Christ and St John the Baptist. The former interrupts the course of the Church’s year, and falls within a cycle of feasts with which it has no inner connection. The Conception of our Blessed Lady, the latest in date of her great feasts, depends naturally upon the date of her birth. Finally, nothing can be said touching the grounds which led to the choice of these dates, for no historical evidence for the first institution of these festivals has come down to us. They have been appointed and sanctioned by custom. We shall first deal with the great festivals of our Lady, the observance of which affected public life. From these we omit Candlemas, originally regarded rather as a festival of our Lord. Three others—the Nativity, Annunciation, and Assumption—can be considered together as far as their institution is concerned, inasmuch as they made their appearance in history at the same period—that is to say, in the seventh century. The reliable evidence for their introduction in Rome is confined to the following; in the later MSS. of the _Gregorianum_ appears a notice which confines the work of Gregory the Great to the first part of the sacramentary. This is the important preface “Hucusque.”[498] In this it is stated the entire preceding part of the book is due to Gregory I., with the exception of what concerns the Nativity and Assumption of our Lady, and a few other matters. From this it follows that the sacramentary used in the time of Gregory I. did not contain these two festivals of the Mother of God. They had been already introduced, however, by the end of the seventh century. This is clear from the fact that they appear in the _Gelesianum_, and, secondly, from a statement in the life of Sergius I. (687-701),[499] to the effect that this pope directed that on the Annunciation, Nativity, and Assumption of our Lady, and in the festival which the Greeks call _Hypapante_, a procession (_litania_) should go from St Adrian’s to St Mary Major’s. These festivals were at that time already observed in Rome, when Sergius ordered these processions as adjuncts to existing festivals. This comprises all the reliable evidence at our disposal regarding these feasts of our Lady.[500]