The historian's life may have few pleasures, but one of its compensations is that he is allowed to eavesdrop. Let us therefore take advantage of this to read the thoughts of Cambyses, as he waits at Acre early in 525 B.C., on the eve of his invasion of Egypt. As doubts begin to overwhelm him, he surveys the difficulties ahead. ‘I am undertaking’, he thinks to himself, ‘something more hazardous than the Medes and the Persians have ever attempted: the conquest of a land six hundred miles long, fed by a river whose very origins are unknown, and whose antiquity is beyond grasp. Worse than this, it contains some three million people, and perhaps more, not to mention its foreign communities, all of whom will need to be governed wisely if they are not to revolt and cause us interminable problems. Its cities are strongly fortified with ramparts, and there are twenty thousand towns; the mouths of its strange river flood unpredictably, and can be controlled by canals and dykes without our knowledge. Whole armies could perish there. True, the Assyrians before us invaded this puzzling country, but that was a short-lived affair and produced nothing but a few obelisks. They did not even dare to dismiss the local governors, who revolted as soon as their backs were turned. The Babylonians came to grief three times at least on its north-east frontier. If this were not enough, there are also the trackless deserts, which few of our men have ever seen.