Apart from the text of Iṣhāq ibn al-Husayn, a series of geographical, historical and bibliographical collections provide information that highlights the continuity of an African presence on Spanish soil. This information can be found in particular in works by Ibn Abī Zar', al-Makarrī, Ibn al-Abbār,  
al-Himyarī, Ibn al-Athīr, Ibn 'Idhārī, Ibn al-Khardabūs, Ibn Khallikān and Ibn Khaldūn (2006, vol. VI, pp. 220-2). It is in Ibn Khallikān (Lagardère, 1989) that we find the most explicit information on the role played by Sudanese soldiers during the famous battle of al-Zallāka, which took place on Friday 12 Rajab $479 \mathrm{AH} / 23$ October 1086 CE. In the record that he dedicates to the Almoravid prince in his bibliographical dictionary, Wafayāt al-a'yān wa 'anbä'abnā' al-zamān, the author talks of the black soldiers who accompanied the European cavalcades of the Saharan Emir, Yūsuf ibn Tāshfīn. They were equipped with armour and shields of lamt (oryx) skins, Indian sabres, long spears and javelins made from beech and fir. While reporting their vigorous intervention on this occasion, the author describes them as leading actors in the defence of the last Muslim kingdoms of Spain.  
We know that this new intervention by the African armies was a result of an urgent plea from the King of Seville, al-Mu'tamid Muhammad ibn Abbad (r. $461 \mathrm{AH} / 1069 \mathrm{CE}-482 \mathrm{AH} / 1090 \mathrm{CE}$ ). Unable to withstand the Castilians and fearing an end as dire as the one that befell the kingdom of Toledo, al-Mu'tamid (as he was known) decided to ask the Africans for help. Other Andalusian kings, advised by qadis and religious men, joined him. Agreeing to their request, the Almoravid prince, Yūsuf ibn Tāshfīn (r. 1071 CE-1106 CE) landed at Algeciras at the head of an expeditionary force of over twelve thousand men made up of Berbers and Sudanese. These figures are undoubtedly all the more unverifiable because they vary constantly in the Arabic texts.