Some nineteenth century Coptic scholars, such as Mikhail Sharubim and Rifa'a al-Tahtawi, split the Roman emperors into two dynasties, a Thirty-Fourth Dynasty for Pagan emperors and a "Thirty-fifth Dynasty" encompassing Christian emperors from Theodosius I to the Muslim conquest of Egypt in 641 AD, although no Christian Roman emperor was ever referred to as pharaoh by the population of ancient Egypt.