Once in North Africa, Christianity spread slowly West from Alexandria and East to Ethiopia. Truth23 wrote 'Through North Africa, Christianity was embraced as the religion of dissent against the expanding Roman Empire. In the 4th century AD the Ethiopian King Ezana made Christianity the kingdom's official religion. In 312 Emperor Constantine made Christianity the official religion of the Roman Empire.'
Actually your European sources do not accurately describe the history correctly.
Exiled Egyptians: the heart of Africa - Google Books ( read especially from page 91)
In 312 CE Christianity was made the official religion of the Roman empire. The Romans ruled Egypt at the time. A short time later the Roman empire split. Egypt became part of the Byzantine Empire from 323 CE. Constantine's declaration to make Christianity the official religion of the empire had two immediate effects on Egypt:
Firstly it allowed the church to enhance the organisation of its administrative structure and to aquire considerable wealth.
Secondly it allowed Christian fanatics to destroy the native Egyptians religious rights, properties and temples.
Here a few examples of the Christian rampage in Egypt.
During a visit to Egpyt in 385 CE Maternus Cynegius, closed the ancient Egyptian temples and forbade sacrifices to Min-Amen.
When Theophilus was made Patriarch of Alexandrai in 391CE he displayed tremondous zeal in destroying ancient Egyptian temples. A wave of destruction swept over the land of Egypt. Tombs were ravaged, walls of ancient monuments scraped, and staues toppled.
In addition to the violation of ancient Egyptian temples the fanatic christians adopted a new script called the Coptic language - basically demotic Egyptian written in Greek characters...
There was unrest and riots, short of civil war in the Delta. The Egyptian refugees at Ta-Apet (Thebes) were active against this virulent bigotry; and frequently attacked the Byzantine strongholds in western oases and Upper Egypt.
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Wherever christianity has appeared in Africa it has resulted in destruction of peoples culture/history and political autonomy.
We haven't even started to talk about King Ezana and his destruction of Meroe the last capital of Kush. The amount of ancient scientific knowledge, architecture, and human history that has been lost in Africa because of Christians /prior to European contact is a tragedy.