II. 2. VIII AND THE INVASION OF DONGOLA 159

As regards the clause in the treaty prohibiting Arab settlement

in Nubia, no doubt it was merely intended as a concessionary make-

weight against the corresponding prohibition of Nubian settlement

in Egypt, and it evidently fell into desuetude at an early date. Although the treaty as a whole seems to have remained in force for

so long, the payment of the requisite tribute must have been re-

garded as the only really important clause, and even this was judici-

ously rendered more palatable to the Nubians by the subsequent exchange of gifts so advantageous to themselves.

VII -^In 656 the Khalifa 'Othman was murdered and the civil war which followed did not leave Egypt unaffected. There had already been a rising against the oppressive rule of 'Abdulla ibn Sa'ad, and

of two successive governors sent out by the Imam 'Ali one had to be removed and the other was poisoned. At Kharibta in the Hauf were

10,000 men determined to avenge 'Othman, and when 'Amr ibn el

'Asi reappeared in 658 with a considerable body of troops as the nominee of Mu'awia, the rival of 'Ali, he had no difficulty in establish-

ing himself for a second period as Governor of Egypt. Two expe-

ditions were sent between 658 and 664 against the Berbers of Libya, but otherwise no outstanding event occurred,

VIII 'Amr died in 664, and between that date and the rise of the Tulunid dynasty in 868 ninety-eight Arab governors ^ ruled Egypt, and the Arab population increased steadily.

The chief occasions of the immigration were the arrivals of new

governors: each one came escorted by an army of anything up to

20,000 men, many of whom never returned to Syria or Arabia^. A proportion of these hordes were Persian, Turkish and other tribes, but the majority were Arabs and would normally be members of the

governor's own tribe. It is interesting, therefore, to analyse the tribal names of the eighty-three different governors who followed 'Amr. We find that in the Ommayyad period, i.e. up to 750 A.D., seven out

to 'Amr after the expedition of 641-2 they offered him a personal gift of 40 slaves: he refused to accept them and handed them back to the envoy, who sold them and bought provisions and wine for the Nubians. This became a regular institution; but after the expedition of 651-2 the governor of Egypt kept the 40 slaves. Accord- ing to the authority cited by Makrizi, viz. a certain Abu Khalifa Hamid ibn Hisham

el Bohtari (Burckhardt calls him " Aly Kheleyfa Homayd Ibn Hesham el Baheyry,"

p. 512), who again gave as his authority the work of one Abu Zacharia (see Makrizi, Khetdt, II, 582), the actual amounts delivered to the Nubians were 1000 ardebs of wheat, 1000 of barley, and 1000 jars of wine for the king, and for every 1000 an extra 300 for the envoys: also 2 fine horses, too pieces of different kinds of cloth, 40 pieces of finer cloth, and a robe, for the king.

^ Lane-Poole, Hist. p. 24. ^ Several of these had two or three terms of office. There were only 83 different governors. See the list given by Lane-Poole {Hist. pp. 45-57).

^ Lane-Poole, Hist. p. 29.