Generally, and apart from a short chronicle attributed to the geographer Ishāq ibn al-Husayn, the texts only refer to a single category of soldiers, the Berbers. However, everything suggests that the initial exploit, which sealed the annexation of a major part of the western world, was that of a combined army, bringing together Berbers and Sudanese; all barely Islamized and only superficially Arabized.  
Obviously, it is difficult to specify the exact number of Sudanese soldiers that landed on the European front in the month of Rajab or Sha'bān in the year $92 \mathrm{AH} /$ April or May 711 CE. From where did they come, exactly? We do not know, neither do we know whether or not they were free. However, some modern historians (Cuoq, 1985, p. 64), wanting to give a categorical opinion, have assigned them a more servile status and Nubian origins. Nothing is less certain, however, especially since the lack of documentation raises multiple problems. It must be said that the documentation for the period prior to the  
second half of the eighth century remains very sparse. It would undoubtedly be ill-advised to follow a single hypothesis in Hispanic history at this point.  
Perhaps it would be appropriate to recall a factor that recurs fairly frequently in medieval historical tradition: the invisibility of a significant portion of the populations living on the edge of the Sahara and who were, clearly, black-skinned. Strangely, this sociological and human reality generally passes unnoticed. Once again, the example of the Almoravid Prince Yūsuf ibn Tāshfin must be quoted. Despite the usual euphemisms drawing attention to his brown complexion, this hero of al-Zallāka was of extremely dark hue (Ibn Khallikān op. cit., vol. VII, p. 125; Ibn Abī Zar, 1860, p. 190; Zerekli, 1986, tome 8, p. 222). Son of a sub-Saharan concubine, Ibn Tāshfin was also completely ignorant of the language of his Arab contacts and communicated with them through interpreters (Makkarī, 1995, vol. VI, p. 124).