By the year 600, most of Africa had embraced the Christian religion. Although more widespread in the north, Christianity was found south of the Sahara as well. It was not universally adopted, as there were many Jews in Africa, especially on the east coast, and some of the primitive pre-religious belief systems, such as animism, survived in isolated regions.
Historians disagree about what happened to Christianity after the Muslim armies swept across north Africa in the late 600's and early 700's, and dominated southern parts of the continent in the following centuries. Was Christianity totally destroyed? Did the Islamic invasions succeed in removing all traces of the faith? Most Christians met one of three fates: they were executed, they converted to Islam, or they fled. But historians debate whether or not there were some who survived and remained in the conquered territories.
The conventional historical view is that the conquest of North Africa by the Islamic Umayyad Caliphate between AD 647–709 effectively ended Christianity in Africa for several centuries. The prevailing view is that the Church at that time lacked the backbone of a monastic tradition and was still suffering from the aftermath of heresies including the so-called Donatist heresy, and this contributed to the earlier obliteration of the Church in the present day Maghreb. Some historians contrast this with the strong monastic tradition in Coptic Egypt, which is credited as a factor that allowed the Coptic Church to remain the majority faith in that country until around after the 14th century.
However, new scholarship has appeared that disputes this. There are reports that the Christian faith persisted in the region from Tripolitania (present-day western Libya) to present-day Morocco for several centuries after the completion of the Islamic conquest by 700. A Christian community is recorded in 1114 in Qal'a in central Algeria. There is also evidence of religious visits after 850 to tombs of Christians outside of the city of Carthage, and evidence of religious contacts with Christians surviving in Muslim-occupied Spain. In addition, calendar reforms adopted in Europe at this time were disseminated amongst the indigenous Christians of Tunis, which would have not been possible had there been an absence of contact with Christians in other parts of the world.
Local Christian communities came under even more pressure when the Muslim fundamentalist regimes of the Almohads and Almoravids came into power, and the record shows demands made that the local Christians of Tunis to convert to Islam. We still have reports of Christian inhabitants and a bishop in the city of Kairouan around 1150 AD - a significant report, since this city was founded by Muslims around 680 AD as their administrative center after their conquest. A letter in Church archives from the 14th century shows that there were still four bishoprics left in North Africa, admittedly a sharp decline from the over four hundred bishoprics in existence at the time of the Islamic conquest. Berber Christians continued to live in Tunis and Nefzaoua in the south of Tunisia up until the early 15th century, and the first quarter of the 15th century, we even read that the native Christians of Tunis, though much assimilated, extended their church, perhaps because the last Christians from all over the Maghreb had gathered there.
By the early 1800's, some regions of Africa persecuted Christians to the extent that these religious communities were secret churches, meeting in homes or remote locations, using codewords to identify themselves to each other and avoid police detection.
