With the fall of Alexandria in 22/642, ‘Amr b. al-’Āṣ, the conqueror of Egypt, realised that in order to maintain all that he had achieved in Egypt, he should assure its security against any possible threat. He might also have realised that the great danger was from the Byzantine power on the sea as well as from the west because of the Byzantine possessions in North Africa. The raids towards the west, in this very early stage, were therefore an absolute necessity to protect Egypt rather than to gain new territories or to obtain booty. The penetration into what is now Libya was undertaken upon the initiative of ‘Amr himself. His strategy was concerned mainly with gaining control of the coastland, but at the same time he thought that any strong and permanent control of the coastland should be accompanied by effective control of the interior. Thus, he set off towards Barqa, the main city in Cyrenaica, at the head of an army which numbered probably about 4,000 tribesmen from the various clans which participated in the conquest of Egypt, especially those from the reinforcements (madadiyyūn) which came to Egypt under al-Zubayr b. al-’Awwām. The majority of these reinforcements were clans from Yaman, such as Mahra, Hadramawt, Khawlān, Mu’āfir, Lakhm and Sadif.¹ Among them were also tribesmen from the various clans of Hijāz, such as Fihr and Banū ‘Abdul’uzza of Quraysh, and al-Ansar, who were now led by ‘Abdullāh b. al-Zubayr.