 New waves of Berber settlers arrived in al-Andalus in the 10th century, brought in as mercenaries by Abd ar-Rahman III to help him in his campaigns to recover Umayyad authority in areas that had thrown off allegiance to the Umayyads during the reigns of the previous emirs.These new Berbers "lacked any familiarity with the pattern of relationships" that had existed in al-Andalus in the 700s and 800s; thus they were not involved in the same web of traditional conflicts and loyalties as the existing Berber garrisons.New frontier settlements were built for the Berber mercenaries who arrived in the 900s.