The Islamization of Egypt occurred after the seventh-century Muslim conquest, in which the Islamic Rashidun Caliphate seized control of Egypt from the Christian dominated Byzantine Empire. Egypt and other conquered territories in Africa gradually underwent a large-scale conversion from Christianity to Islam, motivated in part by a jizya tax for those who refused to convert. Islam became the faith of the majority of the population at some point between the 13th and 14th centuries, and Arabic became the main language, replacing Coptic and Greek, which had previously served as the vernacular and governmental languages, respectively.