This work completes the Ancient History of the East, to which the author has devoted his main attention during the last eighteen years. It is a sequel to his “Parthians,” published in 1873; and carries down the History of Western Asia from the third century of our era to the middle of the seventh. So far as the present writer is aware, no European author has previously treated this period from the Oriental stand-point, in any work aspiring to be more than a mere sketch or outline. Very many such sketches have been published; but they have been scanty in the extreme, and the greater number of them have been based on the authority of a single class of writers. It has been the present author’s aim to combine the various classes of authorities which are now accessible to the historical student, and to give their due weight to each of them. The labors of M. C. Muller, of the Abbe Gregoire Kabaragy Garabed, and of M. J. St. Martin have opened to us the stores of ancient Armenian literature, which were previously a sealed volume to all but a small class of students. The early Arab historians have been translated or analyzed by Kosegarten, Zotenberg, M. Jules Mohl, and others. The coinage of the Sassanians has been elaborately--almost exhaustively--treated by Mordtmann and Thomas. Mr. Fergusson has applied his acute and practised powers to the elucidation of the Sassanian architecture. By combining the results thus obtained with the old sources of information--the classical, especially the Byzantine writers--it has become possible to compose a history of the Sassanian Empire which is at once consecutive, and not absolutely meagre. How the author has performed his task, he must leave it to the public to judge; he will only venture to say that he has spared no labor, but has gone carefully through the entire series of the Byzantine writers who treat of the time, besides availing himself of the various modern works to which reference has been made above. If he has been sometimes obliged to draw conclusions from his authorities other than those drawn by Gibbon, and has deemed it right, in the interests of historic truth, to express occasionally his dissent from that writer’s views, he must not be thought blind to the many and great excellencies which render the “Decline and Fall” one of the best, if not the best, of our histories. The mistakes of a writer less eminent and less popular might have been left unnoticed without ill results. Those of an historian generally regarded as an authority from whom there is no appeal could not be so lightly treated.