According to this programme the collection was to comprise sixteen volumes, besides two volumes of explanations and tables. The first volume was to present documents concerning the life of Jesus Christ and the feasts established in honour of the special events of His life; the second volume would be devoted to the life and the feasts of the Blessed Virgin, and the third to the feasts of the Saints honoured with a more special cult. The twelve succeeding volumes were to give the lives of the saints whose feasts are celebrated respectively in the twelve months of the year, one volume for each month. This calendar arrangement had been prescribed by his superiors, in preference to the chronological order Rosweyde himself favoured. But this presented, especially at that time, formidable difficulties. Lastly, the sixteenth volume was to set forth the succession of martyrologies which had been in use at different periods and in the various Churches of Christendom. The first of the two supplementary volumes was to contain notes and commentaries bearing on the lives divided into eight books treating among other subjects: the authors of the lives, the sufferings of the martyrs, and the images of the saints.