Diodorus of Sicily, 1.55 (C. H. Oldfather, tr.)

After he (Sesoösis) had made ready his army he marched first of all against the Ethiopians who dwell south of Egypt, and after conquering them he forced that people to pay a tribute in ebony, gold, and the tusks of elephants. Then he sent out a fleet of four hundred ships into the Persian Gulf, being the first Egyptian to build warships, and not only took possession of the islands in those waters, but also subdued the coast of the mainland as far as India, while he himself made his way by land with his army and subdued all Asia. Not only did he, in fact, visit the territory which was afterwards won by Alexander of Macedon, but also certain people into whose country Alexander did not cross....

In the same way he brought all the rest of Asia into subjection as well as most of the Cyclades islands. And after he had crossed into Europe and was on his way through the whole length of Thrace, he nearly lost his army through lack of ffod and the difficult nature of the land. Consequently he fixed the limits of his expedition in Thrace.... He dealt gently with all conquered peoples and, after concluding his campaign in nine years, commanded the nations to bring presents each year to Egypt according to their ability, while he himself, assembling a multitude of captives which has never been surpassed and a mass of other booty, returned to his country, having accomplished the greatest deeds of any king of Egypt to his day.

Commentary (by D. Silverman)

Diodorus is writing in the first century BC about events from 1500 years earlier; he has no reliable sources for events which happened this long before his own time. The Egyptians did have some written records of events from this long ago. But these official royal records tend wildly to exaggerate the achievements of certain of the Pharaohs. This passage reflects that tendency. Moreover it would have been impossible for conquest by Egypt on the scale described here to have occurred without leaving its traces in the archeological records of the supposedly conquered lands; this did not happen. Therefore the story told here should be regarded with extreme skepticism.