Christianity had taken root and become one of the components of the Arab state. The entire country was on the verge of a clash between the Nubians and the Muslims. Egypt, led by Amr ibn al-As, was provoked, perhaps in their minds, by what had befallen their co-religionists in defeat at the hands of the Muslims. They began to harass the Egyptian borders, and it seems these attacks took on a disturbing form, prompting Caliph Umar ibn al-Khattab, may God be pleased with him, to order Amr ibn al-As, his governor in Egypt, to invade the land of Nubia.

The Arab presence had its impact on the land of Sudan, such that it can be said that the Arabs of southern Arabia were the dominant element among the Arabs of Sudan before Islam. The first contact of the Muslim Arabs in Egypt with northern Sudan, the kingdom of Makuria, was through the cavalry force sent by Amr ibn al-As to secure trade routes between the two countries. Thus, the land of Nubia was mentioned for the first time in an Arab Islamic document during the period of the peace treaty that Amr ibn al-As granted to the people of Nubia. It stated: "Whoever enters into their peace treaty, be it Romans or Nubians, shall have what they have and shall bear what they bear. And it was stated that the Nubians who responded would live by such and such a number of ranas and such and such a number of horses, on the condition that they would not invade and would not be prevented from exporting or importing trade."

This was after Uqba had met the Nubians in a fierce battle in which the Nubians showed exceptional skill in archery. As a result, Uqba was unable to conquer Nubia. It seems that Amr ibn al-As refused to make peace with them and to declare war on them, after the Arabs had taken Egypt as a base for further conquests and expansion to the south and west, from where Islamic armies would emerge to secure their borders and trade routes, such as the aforementioned campaign that set out to conquer Nubia to the south.

Hence, this campaign, led by Uqba ibn Nafi al-Fihri in the year 21 AH - 642 AD, was the beginning of the first contact between Sudan and the Nile Valley with the Arab conquests through the first gate, where contact began with Nubia, as mentioned by Ibn Abd al-Hakam, the author of 42.