The next martyrologist is Ado, Bishop of Vienne, who has been already mentioned in connection with the "Martyrologium Parvum." Ado was born about the year 800, and died in 875. In his preface, Ado says: "For this work of noting on their proper days the nativities of the Saints, which are generally found confusedly in calendars, I have made use of a venerable and very ancient Martyrology, at Aquileja, sent to a certain holy bishop by the Roman Pontiff, and this was lent me, when at Ravenna, for a few days by a certain religious brother. This I diligently copied, and thought to place it at the head of my work. I have, however, inserted the passions of the Saints somewhat longer in this Martyrology, for the use of the infirm brothers, and those less able to get at books, that they may be able to read out of a little book a compendium to the praise of God and the memory of the martyrs, instead of overhauling a host of big volumes with much labour." The best edition of Ado's Martyrology is that by Geo. Rhodigini, published at Rome, 1740.
There have been many later Martyrologies, but these are of far inferior importance, and need not be here enumerated. In the East, the Greeks had anciently their collections. That of Eusebius probably formed the basis of later Menologies. In the Horology are contained calendars of the Saints for every day with prayers; this portion of the Horology is called the Menology.
The Menology is divided into months, and contains the lives of the Saints, in abridgment, for each day, or the simple commemoration of those whose acts are extant. The Menology of the Greeks is, therefore, much the same as the Latin Martyrology, and there are almost as many Menologies as there are Martyrologies. The principal is that of the Emperor Basil II. (d. 1025), published by Ughelli in his "Italia Sacra." The larger Menologies are entitled "Synaxaria," because they were read in the churches on days of assembly. These lives are very long, and the Menology contains the substance in a condensed form.
The modern Roman Martyrology was drawn up by order of Pope Gregory XIII., who appointed for the purpose eight commissaries, amongst whom was Baronius. It leaves much to be desired, as it bristles with inaccuracies. A fresh edition was issued with some corrections by Benedict XIV. It demands a careful revision. Many of its inaccuracies have been pointed out in the course of this work.