234 A TROPICAL DEPENDENCY Ptolemies. The picture given by Egyptian historians of the last of the Ptolemies is very different from that usually received in the West. Cleopatra's vigilance, they tell us, watched over the extreme limits of the kingdom of Egypt, and some historians have attributed to Cleopatra the wall of Dalouka. There was, therefore, we may infer, the same need under the Ptolemies that there had been under earlier dynasties for defence against the peoples of the Soudan.

It is not surprising that Haussaland and Bornu, which lie between the Bend of the Niger and Lake Chad, and of which the territory occupied at the south-westerly end of the great trade routes of the ancient world a position corresponding to that occupied by Ethiopia proper at the south-eastern end, should have received the inspiration of their civilised development rather from Egypt, and at a later period from the Arabs of the Barbary coasts, than from those Arabs who established the civilisation of the Ommeyade dynasty in Spain. As, however, there is no clear distinction to be made between the Arabs of the west and east, so there will be found comparatively little difference between the medieval civilisation of the western and the eastern portions of the West African Soudan.

The more remarkable differences were of earlier date, when the influence of ancient Egypt was stronger, and when the schismatic Christians of the Roman Empire found their way, under the pressure of persecution, along the same eastern desert road, to the oblivion and the freedom of the south.

During the second and third centuries of our era, when Christians were liable to spasmodic persecution under the pagan emperors of Rome, the African desert was a favourite refuge of the enthusiast, and the conception of winning heaven by preaching the gospel to the most remote nations of the earth was not daunted by the unknown dangers of the Soudan. In the sixth century, when the Emperor Justinian and the Empress Theodora took opposite sides in the great schism of the Incarnation, the Coptic Church,