When he returned from the west to Kairawan, he made his client Tariq (or Tarik) governor of Tangier and of the whole western part of Africa.
Authorized by Musa, Tariq now sent, in Ramadan 91 (July 710), 500 Berbers under the command of Tarif to reconnoitre the, country.
Tariq, thus certain of meeting no serious opposition to his landing, passed into Spain himself with an army composed mainly of Berbers of the Ghomera tribe under the guidance of Julian.
The spot where he landed thence acquired the name of Jebel Tariq, "Mountain of Tariq," afterwards corrupted into Gibraltar.
Having made himself master of Algeciras and thereby secured his communication with Africa, Tariq set out at once in the direction of Cordova.
At the news of the invasion Roderic hastened back and led a numerous army against the combined forces of Tariq and the partisans of Witiza.
Fearing lest he should have escaped to Toledo and should there fit out another army, the partisans of Witiza insisted that Tariq should march immediately against the capital.
Tariq complied with their wishes, notwithstanding the express command of Musa b.
Having made himself master of Ecija and having despatched a detachment under Moghith against Cordova, Tariq took Mentesa (Villanueva de la Fuente) and marched upon Toledo, which he soon conquered.
But, notwithstanding these successes, Tariq knew that his situation was most critical.
Musa, though angered by the disobedience of Tariq, hastened to the rescue and embarked in April 712 with 18,000 men, among them many noble Arabs, and began, advised by Julian, a methodical campaign, with the purpose of establishing and securing a line of communication between the sea and Toledo.
After having taken Seville, Carmona and Merida, he marched from the latter place by the Via Romana to Salamanca, after having ordered Tariq to rejoin him in order to encounter king Roderic. Not far from Tamames the king was defeated and killed.
After this battle Musa reconquered Toledo, which, after the departure of Tariq, had recovered its independence, and entered the capital in triumph.
It seems to be certain that Julian, the imperial count or governor of Ceuta, acting in concert with the family and faction of Witiza, who sought his help against Roderic, provided vessels to transport the Berber Tank (Tariq) across the straits.