In north-eastern Africa two great cultures, one Christian and the other Muslim, had by the middle of the thirteenth century long been expanding their influence over the Semitic- and Cushitic-speaking peoples of the region. The Christian element, planted from Egypt and Syria between the fourth century and the sixth, had its base in the central highland area extending from Tigre in the north through Wag and Lasta to Shoa in the south. It was an area of high plateaux with rich, volcanic soils, which supported a dense and steadily growing population of mountain farmers, who cultivated a whole variety of cereal crops, using ploughs and keeping cattle, horses, mules and donkeys. The Christian clergy were almost entirely monastic, following Monophysite (Coptic) doctrines about the person of Christ, but using the canonical books of the Old and New Testaments, translated from Greek into Geʿez, the old Ethio-Semitic language of the northern highlands, which still remains the liturgical language of the Ethiopian Orthodox Church. Despite its monastic base, or perhaps because of it, Ethiopian Christianity was capable of inspiring large numbers of ordinary lay people to lead lives of great piety. Although few kept the marriage laws, many prayed and fasted and did penance, and sent their children to be taught to take part in a liturgy of music, hymnody and sacred dance.