Here is the passage from Tacitus’s Annals I had in my mind. ‘It was in the Consulate of M. Silanus and L. Norbanus that Germanicus visited Egypt. He gave out that he wished to see to the affairs of the province, but his real object was to make himself acquainted with its antiquities.... Starting from Canopus, and ascending the Nile, he reached the vast remains of Thebes. Enormous structures were still standing, covered with hieroglyphics, which chronicled the bygone grandeur of Egypt. One of the oldest and most distinguished of the priests was ordered to interpret to him the record. He told him that it stated that the population of the country had, at that old time to which it referred, been able to supply an army of 700,000 men of the military age; and that, with that army, King Rameses had conquered Libya, Ethiopia, Media, Persia, Bactria, and Scythia; and the whole of Syria and Armenia, and of the neighbouring Cappadocia. That he had then added to his empire all between the coast of Bithynia on one side, and that of Lycia on the other. They also read the amounts of tribute he had imposed on each nation; the weights of silver and of gold; the number of horses, and of different kinds of arms; the offerings to be made to the temples of ivory and of incense, and the quantity of corn, and of various kinds of vessels. The totals were not less magnificent than those now imposed by Parthian violence, or Roman might. ‘There were also other wonders to which Germanicus directed his attention. Among these were the stone figure of Memnon, which, when struck by the rays of the rising sun, emits a sound resembling the human voice; the Pyramids, which had, in a region of drifting and hardly passable sands, been raised by the rivalry and wealth of kings to the height of mountains; lakes that had been excavated for the storage of the overflow of the Nile; perplexing intricacies and inexplorable recesses, which in no direction could be penetrated by those who might wish to enter them. After he had visited these sights he went to Elephantiné and Syené, the gate formerly of the Roman Empire, which, however, has now been extended to the Red Sea.’ One would much like to know how Tacitus got these particulars of the Prince’s Egyptian tour. Romans were in the habit of keeping diaries, and we cannot doubt but that the practice was followed by one so accomplished and thoughtful as Germanicus. Was it then from the journal of the Prince himself? The family might have allowed the historian to make use of it for the purposes of his forthcoming work. Or was it from the journal of some unconscious Russell of the Prince’s suite? Or had Tacitus himself accompanied the Prince?