[Illustration:  302.jpg FORTRESS NEAR MOUNT SINAI]

The temples of Thebes were the citadels of the capital, and the temples of Elephantine guarded the frontier.  So now, when the military prefect is too weak to make himself obeyed, the emperor tries to govern through means of the Christian priesthood; and when it is necessary for the Egyptians to defend their own frontier, he builds a monastery and garrisons it with monks.

Part of the Egyptian trade to the East was carried on through the islands of Ceylon and Socotra; but it was chiefly in the hands of uneducated Arabs of Ethiopia, who were little able to communicate to the world much knowledge of the countries from which they brought their highly valued goods.  At Ceylon they met with traders from beyond the Ganges and from China, of whom they bought the silk which Europeans had formerly thought a product of Arabia.  At Ceylon was a Christian church, with a priest and a deacon, frequented by the Christians from Persia, while the natives of the place were pagans.  The coins there used were Roman, borne thither by the course of trade, which during so many centuries carried the gold and silver eastward.  The trade was lately turned more strongly into this channel because a war had sprung up between the two tribes of Jewish Arabs, the Hexumitae of Abyssinia on the coast of the Red Sea near Adule, and the Homeritae who dwelt in Arabia on the opposite coast, at the southern end of the Red Sea.  The Homeritae had quarrelled with the Alexandrian merchants in the Indian trade, and had killed some of them as they were passing their mountains from India to the country of the Hexumitae.

Immediately after these murders the Hexumitae found the trade injured, and they took up arms to keep the passage open for the merchants.  Hadad their king crossed the Red Sea and conquered his enemies; he put to death Damianus, the King of the Homeritse, and made a new treaty with the Emperor of Constantinople.  The Hexumitae promised to become Christians.  They sent to Alexandria to beg for a priest to baptise them, and to ordain their preachers; and Justinian sent John, a man of piety and high character, the dean of the church of St. John, who returned with the ambassadors and became bishop of the Hexumitae.

It was possibly this conquest of the Homeritae by Hadad, King of the Hexumitae, which was recorded on the monument of Adule, at the foot of the inscription set up eight centuries earlier by Ptolemy Euergetes.  The monument is a throne of white marble.  The conqueror, whose name had been broken away before the inscription was copied, there boasts that he crossed over the Red Sea and made the Arabians and Sabaaans pay him tribute.  On his own continent he defeated the tribes to the north of him, and opened the passage from his own country to Egypt; he also marched eastward, and conquered the tribes on the African incense coast; and lastly, he crossed the Astaborus to the snowy mountains in which that branch of the Nile rises, and conquered the tribes between that stream and the Astapus.  This valuable inscription, which tells us of snowy mountains within the tropics, was copied by Cosmas, a merchant of Alexandria, who passed through Adule on his way to India.