Christianity in the 7th century

The Western (Latin) and Eastern (Greek) divisions of Christianity began to take on distinctive shape in 7th-century Christianity. Whereas in the East the Church maintained its structure and character and evolved more slowly, in the West the Bishops of Rome (the popes) were forced to adapt more quickly and flexibly to drastically changing circumstances. In particular, whereas the bishops of the East maintained clear allegiance to the Eastern Roman emperor, the Bishop of Rome, while maintaining nominal allegiance to the Eastern emperor, was forced to negotiate delicate balances with the "barbarian rulers" of the former Western provinces. Although the greater number of Christians remained in the East, the developments in the West would set the stage for major developments in the Christian world during the later Middle Ages.

During the 7th century an Arabian religious leader named Muhammad began to spread an Abrahamic faith, similar to that of Christianity and Judaism, which would become one of the greatest challenges to the medieval Christian Church. Large portions of the Arabian Peninsula had been conquered by the time of his death, and the emerging caliphate would soon begin expanding beyond Arabia as the Byzantine and Persian empires had just been crippled during the Byzantine–Sasanian War of 602–628.