Literary evidence for Christianity in North Africa in the first three centuries comes from Tertullian, Minucius Felix, Cyprian, Commodian, Pseudo-Cyprian, and various homilies and stories of martyrdom. It illustrates the beliefs of the Christian communities, their structures and practices. African social organisation was primarily tribal until the arrival of the Phoenicians, whose culture centred on cities. In general, Africans used Romanisation when it was to their own advantage. The Semitic roots of Punic religion raise the question of the origins of Christianity in Rome. There was great respect for Christians at Rome, but no tradition of a foundation from that city. The intransigence of African Christianity manifests itself from the very beginning through martyrdom and apology. Christians in Africa were persecuted intermittently from 180 until 305. True heirs of African Christianity, they maintained literal and strict interpretations of scripture and a culture of martyrdom. They fostered unity and collegiality among those who continued to oppose the Roman state.