 Throughout the ninth century, the Berber garrisons were one of the main military supports of the Umayyad regime.Although they had caused numerous problems for Abd ar-Rahman I, Collins suggests that by the reign of Al-Hakam, the Berber conflicts with Arabs and native Iberians meant that Berbers could only look to the Umayyad regime for support and patronage, developing solid ties of loyalty to the emirs.However, they were also difficult to control, and by the end of the ninth century the Berber frontier garrisons disappear from the sources.