At present I shall content myself with a single observation. The biographers, who, under the reigns of Diocletian and Constantine, composed, or rather compiled, the lives of the Emperors, from Hadrian to the sons of Carus, are usually mentioned under the names of Ælius Spartianus, Julius Capitolinus, Ælius Lampridius, Vulcatius Gallicanus, Trebellius Pollio and Flavius Vopiscus. But there is so much perplexity in the titles of the MSS., and so many disputes have arisen among the critics (see Fabricius, Biblioth. Latin. l. iii. c. 6) concerning their number, their names, and their respective property, that for the most part I have quoted them without distinction, under the general and well-known title of the _Augustan History._ Preface To The Fourth Volume Of The Original Quarto Edition. I now discharge my promise, and complete my design, of writing the History of the Decline and Fall of the Roman Empire, both in the West and the East. The whole period extends from the age of Trajan and the Antonines, to the taking of Constantinople by Mahomet the Second; and includes a review of the Crusades, and the state of Rome during the middle ages. Since the publication of the first volume, twelve years have elapsed; twelve years, according to my wish, “of health, of leisure, and of perseverance.” I may now congratulate my deliverance from a long and laborious service, and my satisfaction will be pure and perfect, if the public favor should be extended to the conclusion of my work.