There were about 1300 manuscripts regarding lives of the saints in the libraries of Belgium. Rosweyde obtained copies of most of them. He pursued his project, which he announced publicly in 1607, as well as the plan he proposed to follow. Under the title: "Fasti sanctorum quorum vitae in belgicis bibliothecis manuscriptiae", he gave in a little volume in 16mo., published by the Plantin press at Antwerp, an alphabetical list of the names of the saints whose acts had been either found by him or called to his attention in old manuscript collections. This list filled fifty pages; the prefatory notice in which he indicates the character and arrangement of his work, as he had conceived it, takes up fourteen. Finally, the work contains an appendix of twenty-six pages containing the unpublished acts of the passion of the Cilician martyrs, Tharsacus, Probus, and Andronicus, which Rosweyde regarded—wrongly—as the authentic official report from the pen of a clerk of the court of the Roman tribunal.