Diodôros was born at Agyrium, a city in the interior of Sicily, and was a contemporary of Julius Caesar and the Emperor Augustus. It was the great ambition of his life to write an universal history, and having this in view he travelled over a great part of Europe and Asia in order to acquire a more accurate knowledge of countries and nations than could be obtained from merely reading books. In Rome, where a far greater number of the ancient documents which he required to consult had been collected than were to be found elsewhere, he resided for a considerable time. He spent thirty years in the composition of his work, to which he gave the name of _Bibliothêkê_, which indicated that it formed quite _a library_ in itself, embracing, as it did, the history of all ages and all countries. It consisted of forty books, which he divided into three great sections: 1st, the mythical period previous to the Trojan war; 2d, the period thence to the death of Alexander the Great; 3d, the period from Alexander to the beginning of Caesar’s Gallic wars. Considerable portions of the _Bibliothêkê_ are lost, but all the books relating to the period with which we are concerned are still extant. Diodôros constructed his narrative upon the plan of annals, placing the events of each year side by side without regard to their intrinsic connection. The value of the work is greatly impaired by the author’s evident want of critical discernment; he mixes up history with fiction, shows frequently that he has misunderstood his authorities, and advances statements which are mutually contradictory. His style is, however, pleasing, having the merits of simplicity and clearness. In his second book he gives a description of India epitomized from Megasthenes. His account of Alexander’s career in India records some interesting particulars of which we should otherwise have remained ignorant. He seems to have drawn largely from the same sources as Curtius. JUSTINUS FRONTINUS