Procopius, a Greek historian of Cæsarea, secretary to Belisarius, a general during the reign of Justinian, records some important facts of this pestilence, which ravaged the whole world; it lasted four months at Constantinople, and, when at its height, it is supposed that 10,000 perished daily in that city. Nicephorus also describes this pestilential period, and remarks that “certain little marks appeared on the doors and outside of their houses, on their garments, and on their utensils; some white crusts of a peculiar deposition from the air adhered to all things, as damp moulds do on the walls or dwellings, and dew on grass.” In the year 590, at Rome, in the time of Pope Pelagius the Second, there was a horribly destructive pestilence prevalent, and also in Spain. The air was observed to be impregnated with a kind of mist and fœtidness, which by irritation induced a sneezing; hence the custom of saluting a person sneezing with the expression “Dominus tecum,” or some similar expression, a practice which has reached our time. The year following, 591, Britain suffered from a severe pestilence, also Turenne, and the provinces of Arragon and Vivares. This disease was called _inguinaria_, because buboes were formed more particularly in the groin. In the year 610, pestilential small-pox committed great ravages at Mecca. A.D. 614, epidemic elephantiasis prevailed in Italy, and three years subsequently, an epidemic pestilence, resembling the true plague. In Syria, Arabia, &c., a great pestilence prevailed A.D. 639 and 640. A.D. 654, Constantinople was devastated by a severe pestilence. In the year of our Lord 664, a sudden pestilence (man-cyalm), after depopulating the southern coasts of Britain, infected the provinces of the Northumbrians, and, spreading for a long time in every direction, destroyed great numbers. The year following, 665, it reached Italy, causing great destruction of life. Fordum (Scriptores, xv. vol. iii. page 646) cites a Greek historian to the effect that dire mortality prevailed, A.D. 669, all over Europe, which did not spare the remotest islands, Great Britain and Ireland. England also suffered greatly, A.D. 672, from pestilence, at which period universal disease appeared in Syria and Mesopotamia. England and Ireland were revisited by pestilence, A.D. 679, beginning in the month of July, and continuing until the end of September. Rome suffered from similar ravages the following year, and in A.D. 683, England again suffered from severe epidemic disease, which lasted three years. A.D. 685, Syria and Libya were laid waste by disease. Ireland suffered from a severe epidemic the same year. From a singular portion of history which has been preserved in the records of the church of Mayo, we find that the ‘ignis sacer,’ or pestilence originating from famine, was similar to and contemporary with the pestilence ‘man-cyalm,’ which raged among the British after the departure of the Romans from Britain (664).