When one considers the details presented by calendars, one is bound to acknowledge that the Roman _Depositio Martyrum_ stands at the head of this long line of liturgical documents, and was the model after which they were composed. Like them, the _Depositio Martyrum_ was drawn up according to months, and commenced with Christmas. Like them, it contained the official list of the martyrs who received ecclesiastical veneration in the local church of Rome in the fourth century. Were it not so, it would not have deserved to be incorporated in the Philocalian collection, the _Hemerologium Valentini_, since this comprised only official documents; had it not been official it would not have been worth transcribing. CONCLUSION All estates of men in the Church have had their share in the formation of the ecclesiastical year, for the growth of the Church’s festivals has continued without interruption from the beginning until now, and has extended over all the countries of Christendom. Having wended our way through the centuries and arrived at the conclusion of our work, it is a pleasure to render our tribute of thanks and praise to the men who have in the past made this sphere of study their own. The few writers of the Middle Ages who treated the Church’s year and the festivals of the saints in a comprehensive manner were entirely occupied with contributing to the correct performance of ecclesiastical ceremonies, and with explaining why each ceremony must be done in one way and not in another. They not infrequently brought allegorical and symbolical considerations to bear on the question. In more modern times, Cornelius Schulting, a native of Steenwijk in North Holland, and afterwards professor of theology at Cologne and canon of St Andrew’s († 1604) undertook a full exposition of the matter; his object was mainly practical, and his work can only be regarded as a first attempt. The keen controversialist, Jacobus Gretser S.J. († 1625), is more occupied with his polemic against the Calvinists than with lucid demonstration. More in harmony with modern requirements, is the French oratorian Louis Thomassin, a native of Aix in Provence, and a partisan of Port Royal, who died in 1695; he wrote a small compendium which may be used with profit at the present day.