2. The _Gelasianum_, so called after Gelasius I. (492-496). This pope did actually compose some liturgical books, but the _volumen sacramentorum_, ascribed to him by Gennadius, cannot have been one of them, since it contains the four festivals of our Lady which were celebrated in Rome only after Gregory the Great. On the other hand it does not contain the stations for the Thursdays in Lent introduced by Gregory II. (715-731); consequently, it represents the liturgical usages of the seventh century, _i.e._ of the period after St Gregory the Great, and bears the name of Gelasius incorrectly. It consists of three books: (1) _De Tempore_, beginning with Christmas; (2) _De Sanctis_, beginning with the 1st January; and (3) masses for the ordinary Sundays, votive masses, and masses for the dead. The number of prefaces contained in the sacramentary amounts to over a hundred. The Stowe Missal, which is independent of the _Gelasianum_, gives the _canon Gelasii Papæ_. This book was drawn up in Rome and was intended for local usage, but we only possess the MSS., which were meant for the churches of France; the most ancient belongs to the end of the seventh century, and was written apparently for the Abbey of St Denys (Cod. Vat. Reg. Sueciæ, 316). The other existing codices only give an edition specially adapted from the original Roman book for use in the Frankish Empire; this is shown by the prayer, “Respice propitius ad Romanum sive Francorum imperium.” 3. _The Gregorianum._ This represents the Roman rite of the period of Pope Adrian I. (772-795) and Charlemagne. It is entirely a compilation of Roman origin belonging to the eighth century, destined originally for the use of the popes but afterwards adapted for general use. The canon stands at the head of the work, which commences with Christmas, but Advent comes at the end of the _Proprium de Tempore_. The _Agnus Dei_, added to the text of the mass by Pope Sergius I., is given here in its place, while it is absent from _Gelasianum_.[739] The earliest mention of this work is in the collection of letters of the popes of the eighth century known as the _Codex Carolinus_, in a letter of Adrian I. to Charlemagne who received a copy of the work from Adrian between 784 and 791,[740] from which date it was introduced into the Frankish Empire, copied, and circulated, and also added to. In his letter Adrian ascribes a personal share in the production of the work to his predecessor Gregory, relying, of course, on the tradition of his Church.[741] 4. This last-named book gradually supplanted the ancient liturgies and service-books of Gaul; of these we possess the _Sacramentarium Gallicanum_, along with its lectionary, the _Missale Gothico-Gallicanum_, and the _Missale Francorum_;[742] the Mozarabic missal and breviary are also very important documents.