The Beja had launched a surprise raid on Egypt, catching the Muslims unawares as they performed the Eid prayer, inflicting a great slaughter upon them. They looted whatever they could from the Muslims and returned to their lands. It appears from the account of Al-Balawi that the campaign, which set out during the reign of Ahmad ibn Tulun and was led by "Abu Abd al-Rahman al-Umari," was prepared through his personal effort and out of his own volition, as Al-Balawi states: "So this al-Umari went out, angered for the sake of God Almighty and for the Muslims. He lay in wait for them on their path until they approached, as was their custom, and he ambushed them and killed their leader, the one-eyed man himself." The account of al-Umari also suggests that Ahmad ibn Tulun was the one who sent him, as he says: "I did not go out seeking corruption in the land, and the proof of that is his statement that I did not harm a Muslim or a protected person, but rather I went out in pursuit of the enemies of the Muslims until God sufficed us from them."

Al-Umari's direction was towards the region of Shingir, south of Alaqi, where Arab tribes from the Levant, including the tribe of Sa'd al-Ashira and Qays and 'Aylan, had come. After they obtained permission from the Nubians for permanent residence in the region of Marbis, in addition to the participation of the tribes of Rabi'a and Juhayna, this campaign was very active in the land of Nubia.

Al-Umari's expedition had several multiple objectives. The Eastern Desert, where the Beja were, was not the only target of this campaign. Rather, it encompassed the Nile regions and was a large-scale campaign. The purpose was not to discover new mineral regions, as some historians have tried to assert. However, what al-Umari mentioned about himself was that he went out in pursuit of the enemies of the Muslims until God sufficed us from them, and that we did not seek corruption in the land. The discovery of new gold and mineral deposits was part of the plan of the invasion in that direction, as well as curbing the Beja and disciplining the inhabitants of those lands. In response to their repeated raids on Egypt and their continuous harassment of the Arabs who had migrated and settled in those lands, seeking minerals and spreading the Islamic call, we find that al-Umari, after he had eliminated the power of the Beja and broken their might, turned west towards the Nile in the "region of Marbis," where he expelled the ruler of Marbis, destroyed its city, and captured many of its inhabitants.